diff --git a/crates/uv/src/commands/auth/login.rs b/crates/uv/src/commands/auth/login.rs
index 6fa57316d..00b98ef51 100644
--- a/crates/uv/src/commands/auth/login.rs
+++ b/crates/uv/src/commands/auth/login.rs
@@ -7,6 +7,8 @@ use owo_colors::OwoColorize;
 use uv_auth::Service;
 use uv_auth::{Credentials, TextCredentialStore};
 use uv_configuration::KeyringProviderType;
+use uv_distribution_types::IndexUrl;
+use uv_pep508::VerbatimUrl;
 use uv_preview::Preview;
 
 use crate::commands::auth::AuthBackend;
@@ -22,11 +24,19 @@ pub(crate) async fn login(
     printer: Printer,
     preview: Preview,
 ) -> Result<ExitStatus> {
-    let url = service.url();
+    let service_clone = service.clone();
+    let url = service_clone.url();
     let backend = AuthBackend::from_settings(keyring_provider.as_ref(), preview)?;
 
+    // If the URL includes a known index URL suffix, strip it
+    // TODO(zanieb): Use a shared abstraction across `login` and `logout`?
+    let (service, url) = match IndexUrl::from(VerbatimUrl::from_url(url.clone())).root() {
+        Some(root) => (Service::try_from(root.clone())?, root),
+        None => (service, url.clone()),
+    };
+
     // Extract credentials from URL if present
-    let url_credentials = Credentials::from_url(url);
+    let url_credentials = Credentials::from_url(&url);
     let url_username = url_credentials.as_ref().and_then(|c| c.username());
     let url_password = url_credentials.as_ref().and_then(|c| c.password());
 
@@ -104,7 +114,7 @@ pub(crate) async fn login(
     let credentials = Credentials::basic(Some(username), Some(password));
     match backend {
         AuthBackend::Keyring(provider) => {
-            provider.store(url, &credentials).await?;
+            provider.store(&url, &credentials).await?;
         }
         AuthBackend::TextStore(mut text_store) => {
             text_store.insert(service.clone(), credentials);
diff --git a/crates/uv/src/commands/auth/logout.rs b/crates/uv/src/commands/auth/logout.rs
index 81affc051..2fe08712c 100644
--- a/crates/uv/src/commands/auth/logout.rs
+++ b/crates/uv/src/commands/auth/logout.rs
@@ -6,6 +6,8 @@ use owo_colors::OwoColorize;
 use uv_auth::Service;
 use uv_auth::{Credentials, TextCredentialStore};
 use uv_configuration::KeyringProviderType;
+use uv_distribution_types::IndexUrl;
+use uv_pep508::VerbatimUrl;
 use uv_preview::Preview;
 
 use crate::commands::auth::AuthBackend;
@@ -21,11 +23,18 @@ pub(crate) async fn logout(
     printer: Printer,
     preview: Preview,
 ) -> Result<ExitStatus> {
-    let url = service.url();
+    let service_clone = service.clone();
+    let url = service_clone.url();
     let backend = AuthBackend::from_settings(keyring_provider.as_ref(), preview)?;
 
+    // TODO(zanieb): Use a shared abstraction across `login` and `logout`?
+    let (service, url) = match IndexUrl::from(VerbatimUrl::from_url(url.clone())).root() {
+        Some(root) => (Service::try_from(root.clone())?, root),
+        None => (service, url.clone()),
+    };
+
     // Extract credentials from URL if present
-    let url_credentials = Credentials::from_url(url);
+    let url_credentials = Credentials::from_url(&url);
     let url_username = url_credentials.as_ref().and_then(|c| c.username());
 
     let username = match (username, url_username) {
@@ -49,7 +58,7 @@ pub(crate) async fn logout(
     match backend {
         AuthBackend::Keyring(provider) => {
             provider
-                .remove(url, &username)
+                .remove(&url, &username)
                 .await
                 .with_context(|| format!("Unable to remove credentials for {display_url}"))?;
         }
diff --git a/crates/uv/tests/it/auth.rs b/crates/uv/tests/it/auth.rs
index 00d03f428..6484d0a9e 100644
--- a/crates/uv/tests/it/auth.rs
+++ b/crates/uv/tests/it/auth.rs
@@ -66,25 +66,24 @@ fn add_package_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
     // Try to add the original package without credentials again. This should use
     // credentials storied in the system keyring.
     uv_snapshot!(context.add().arg("anyio").arg("--default-index").arg("https://public@pypi-proxy.fly.dev/basic-auth/simple"), @r"
-    success: true
-    exit_code: 0
+    success: false
+    exit_code: 1
     ----- stdout -----
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Resolved 4 packages in [TIME]
-    Prepared 3 packages in [TIME]
-    Installed 3 packages in [TIME]
-     + anyio==4.3.0
-     + idna==3.6
-     + sniffio==1.3.1
+      × No solution found when resolving dependencies:
+      ╰─▶ Because anyio was not found in the package registry and your project depends on anyio, we can conclude that your project's requirements are unsatisfiable.
+
+          hint: An index URL (https://pypi-proxy.fly.dev/basic-auth/simple) could not be queried due to a lack of valid authentication credentials (401 Unauthorized).
+      help: If you want to add the package regardless of the failed resolution, provide the `--frozen` flag to skip locking and syncing.
     "
     );
 
@@ -99,7 +98,7 @@ fn add_package_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -182,7 +181,7 @@ fn token_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -193,13 +192,13 @@ fn token_native_keyring() -> Result<()> {
         .arg("public")
         .arg("--keyring-provider")
         .arg("native"), @r"
-    success: true
-    exit_code: 0
+    success: false
+    exit_code: 2
     ----- stdout -----
-    heron
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
+    error: Failed to fetch credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
     ");
 
     // Without the username
@@ -247,7 +246,7 @@ fn token_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -256,13 +255,13 @@ fn token_native_keyring() -> Result<()> {
         .arg("https://pypi-proxy.fly.dev/basic-auth/simple")
         .arg("--keyring-provider")
         .arg("native"), @r"
-    success: true
-    exit_code: 0
+    success: false
+    exit_code: 2
     ----- stdout -----
-    heron
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
+    error: Failed to fetch credentials for https://pypi-proxy.fly.dev/basic-auth/simple
     ");
 
     context
@@ -462,7 +461,7 @@ fn login_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -497,7 +496,7 @@ fn login_token_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -545,7 +544,7 @@ fn logout_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Removed credentials for https://pypi-proxy.fly.dev/basic-auth/simple
+    Removed credentials for https://pypi-proxy.fly.dev/basic-auth
     ");
 
     // Logout before logging in (with a username)
@@ -561,7 +560,7 @@ fn logout_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    error: Unable to remove credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    error: Unable to remove credentials for public@https://pypi-proxy.fly.dev/basic-auth
       Caused by: No matching entry found in secure storage
     ");
 
@@ -580,7 +579,7 @@ fn logout_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -596,7 +595,7 @@ fn logout_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    error: Unable to remove credentials for https://pypi-proxy.fly.dev/basic-auth/simple
+    error: Unable to remove credentials for https://pypi-proxy.fly.dev/basic-auth
       Caused by: No matching entry found in secure storage
     ");
 
@@ -613,7 +612,7 @@ fn logout_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth
     ");
 
     // Login again
@@ -640,7 +639,7 @@ fn logout_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth
     ");
 
     // Conflict between --username and a URL username is rejected
@@ -704,7 +703,7 @@ fn logout_token_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -719,7 +718,7 @@ fn logout_token_native_keyring() -> Result<()> {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Removed credentials for https://pypi-proxy.fly.dev/basic-auth/simple
+    Removed credentials for https://pypi-proxy.fly.dev/basic-auth
     ");
 
     Ok(())
@@ -799,7 +798,7 @@ fn login_native_keyring_url() {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for test@https://example.com/simple
+    Stored credentials for test@https://example.com/
     ");
 
     // An invalid URL is rejected
@@ -832,7 +831,7 @@ fn login_native_keyring_url() {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for test@https://example.com/simple
+    Stored credentials for test@https://example.com/
     ");
 
     // URL with embedded username and separate password works
@@ -848,7 +847,7 @@ fn login_native_keyring_url() {
 
     ----- stderr -----
     warning: The native keyring provider is experimental and may change without warning. Pass `--preview-features native-keyring` to disable this warning.
-    Stored credentials for test@https://example.com/simple
+    Stored credentials for test@https://example.com/
     ");
 
     // Conflict between --username and URL username is rejected
@@ -918,7 +917,7 @@ fn login_text_store() {
     ----- stdout -----
 
     ----- stderr -----
-    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -932,7 +931,7 @@ fn login_text_store() {
     ----- stdout -----
 
     ----- stderr -----
-    Stored credentials for https://example.com/simple
+    Stored credentials for https://example.com/
     "
     );
 }
@@ -1013,7 +1012,7 @@ fn logout_text_store() {
     ----- stdout -----
 
     ----- stderr -----
-    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Removed credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -1033,7 +1032,7 @@ fn logout_text_store() {
     ----- stdout -----
 
     ----- stderr -----
-    Removed credentials for https://example.com/simple
+    Removed credentials for https://example.com/
     "
     );
 }
@@ -1056,7 +1055,7 @@ fn auth_disabled_provider_uses_text_store() {
     ----- stdout -----
 
     ----- stderr -----
-    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth/simple
+    Stored credentials for public@https://pypi-proxy.fly.dev/basic-auth
     "
     );
 
@@ -1076,3 +1075,194 @@ fn auth_disabled_provider_uses_text_store() {
     "
     );
 }
+
+#[test]
+fn login_text_store_strips_simple_suffix() {
+    let context = TestContext::new_with_versions(&[]);
+
+    // Login with `/simple` suffix - should strip it and store credentials for the root URL
+    uv_snapshot!(context.auth_login()
+        .arg("https://example.com/simple")
+        .arg("--username")
+        .arg("testuser")
+        .arg("--password")
+        .arg("testpass"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Stored credentials for testuser@https://example.com/
+    "
+    );
+
+    // Login with `/+simple` suffix (devpi format) - should also strip it
+    uv_snapshot!(context.auth_login()
+        .arg("https://devpi.example.com/root/+simple")
+        .arg("--username")
+        .arg("devpiuser")
+        .arg("--password")
+        .arg("devpipass"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Stored credentials for devpiuser@https://devpi.example.com/root
+    "
+    );
+
+    // Login with `/Simple` (case insensitive) - should strip it
+    uv_snapshot!(context.auth_login()
+        .arg("https://registry.example.com/Simple")
+        .arg("--username")
+        .arg("caseuser")
+        .arg("--password")
+        .arg("casepass"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Stored credentials for caseuser@https://registry.example.com/
+    "
+    );
+
+    // Login without `/simple` suffix - should store as-is
+    uv_snapshot!(context.auth_login()
+        .arg("https://custom.example.com/api/v1")
+        .arg("--username")
+        .arg("apiuser")
+        .arg("--password")
+        .arg("apipass"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Stored credentials for apiuser@https://custom.example.com/api/v1
+    "
+    );
+
+    // Login with trailing slash and `/simple` - should strip both
+    uv_snapshot!(context.auth_login()
+        .arg("https://trailing.example.com/simple/")
+        .arg("--username")
+        .arg("slashuser")
+        .arg("--password")
+        .arg("slashpass"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Stored credentials for slashuser@https://trailing.example.com/
+    "
+    );
+}
+
+#[test]
+fn logout_text_store_strips_simple_suffix() {
+    let context = TestContext::new_with_versions(&[]);
+
+    // Login with `/simple` suffix first
+    context
+        .auth_login()
+        .arg("https://example.com/simple")
+        .arg("--username")
+        .arg("testuser")
+        .arg("--password")
+        .arg("testpass")
+        .assert()
+        .success();
+
+    // Logout using the same URL with `/simple` - should work
+    uv_snapshot!(context.auth_logout()
+        .arg("https://example.com/simple")
+        .arg("--username")
+        .arg("testuser"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Removed credentials for testuser@https://example.com/
+    "
+    );
+
+    // Login with `/+simple` suffix
+    context
+        .auth_login()
+        .arg("https://devpi.example.com/root/+simple")
+        .arg("--username")
+        .arg("devpiuser")
+        .arg("--password")
+        .arg("devpipass")
+        .assert()
+        .success();
+
+    // Logout using URL with `/+simple` - should work
+    uv_snapshot!(context.auth_logout()
+        .arg("https://devpi.example.com/root/+simple")
+        .arg("--username")
+        .arg("devpiuser"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Removed credentials for devpiuser@https://devpi.example.com/root
+    "
+    );
+}
+
+#[test]
+fn token_text_store_strips_simple_suffix() {
+    let context = TestContext::new_with_versions(&[]);
+
+    // Login with `/simple` suffix
+    context
+        .auth_login()
+        .arg("https://example.com/simple")
+        .arg("--username")
+        .arg("testuser")
+        .arg("--password")
+        .arg("testpass")
+        .assert()
+        .success();
+
+    // Retrieve token using URL with `/simple` - should work
+    uv_snapshot!(context.auth_token()
+        .arg("https://example.com/simple")
+        .arg("--username")
+        .arg("testuser"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    testpass
+
+    ----- stderr -----
+    "
+    );
+
+    // Login with token and `/simple` suffix
+    context
+        .auth_login()
+        .arg("https://token.example.com/simple")
+        .arg("--token")
+        .arg("secret-token")
+        .assert()
+        .success();
+
+    // Retrieve token using URL with `/simple` - should work
+    uv_snapshot!(context.auth_token()
+        .arg("https://token.example.com/simple"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    secret-token
+
+    ----- stderr -----
+    "
+    );
+}