diff --git a/crates/uv-macros/src/lib.rs b/crates/uv-macros/src/lib.rs
index d32e908fe..db2cc9853 100644
--- a/crates/uv-macros/src/lib.rs
+++ b/crates/uv-macros/src/lib.rs
@@ -143,6 +143,21 @@ pub fn attribute_env_vars_metadata(_attr: TokenStream, input: TokenStream) -> To
         return quote! { #ast #(#added_in_errors)* }.into();
     }
 
+    let env_var_names = ast.items.iter().filter_map(|item| {
+        if let ImplItem::Const(item) = item {
+            let syn::Expr::Lit(syn::ExprLit {
+                lit: syn::Lit::Str(lit),
+                ..
+            }) = &item.expr
+            else {
+                return None;
+            };
+            Some(lit.value())
+        } else {
+            None
+        }
+    });
+
     let struct_name = &ast.self_ty;
     let pairs = constants.iter().map(|(name, doc, added_in, _span)| {
         if let Some(added_in) = added_in {
@@ -160,6 +175,11 @@ pub fn attribute_env_vars_metadata(_attr: TokenStream, input: TokenStream) -> To
             pub fn metadata<'a>() -> &'a [(&'static str, &'static str, Option<&'static str>)] {
                 &[#(#pairs),*]
             }
+
+            /// Returns all environment variable names defined as constants (including hidden ones).
+            pub fn all_names() -> &'static [&'static str] {
+                &[#(#env_var_names),*]
+            }
         }
     };
 
diff --git a/crates/uv/tests/it/common/mod.rs b/crates/uv/tests/it/common/mod.rs
index 85e7e290f..a742793a6 100644
--- a/crates/uv/tests/it/common/mod.rs
+++ b/crates/uv/tests/it/common/mod.rs
@@ -1444,6 +1444,9 @@ impl TestContext {
         command
     }
 
+    /// The path to the Python interpreter in the venv.
+    ///
+    /// Don't use this for `Command::new`, use `Self::python_command` instead.
     pub fn interpreter(&self) -> PathBuf {
         let venv = &self.venv;
         if cfg!(unix) {
@@ -1726,8 +1729,39 @@ impl TestContext {
 
     /// Creates a new `Command` that is intended to be suitable for use in
     /// all tests, but with the given binary.
+    ///
+    /// Clears environment variables defined in [`EnvVars`] to avoid reading
+    /// test host settings.
     fn new_command_with(bin: &Path) -> Command {
-        Command::new(bin)
+        let mut command = Command::new(bin);
+
+        let passthrough = [
+            // For debugging tests.
+            EnvVars::RUST_LOG,
+            EnvVars::RUST_BACKTRACE,
+            // Windows System configuration.
+            EnvVars::SYSTEMDRIVE,
+            // Work around small default stack sizes and large futures in debug builds.
+            EnvVars::RUST_MIN_STACK,
+            EnvVars::UV_STACK_SIZE,
+            // Allow running tests with custom network settings.
+            EnvVars::ALL_PROXY,
+            EnvVars::HTTPS_PROXY,
+            EnvVars::HTTP_PROXY,
+            EnvVars::NO_PROXY,
+            EnvVars::SSL_CERT_DIR,
+            EnvVars::SSL_CERT_FILE,
+            EnvVars::UV_NATIVE_TLS,
+        ];
+
+        for env_var in EnvVars::all_names()
+            .iter()
+            .filter(|name| !passthrough.contains(name))
+        {
+            command.env_remove(env_var);
+        }
+
+        command
     }
 }
 
@@ -1790,7 +1824,7 @@ pub fn get_python(version: &PythonVersion) -> PathBuf {
 
 /// Create a virtual environment at the given path.
 pub fn create_venv_from_executable<P: AsRef<Path>>(path: P, cache_dir: &ChildPath, python: &Path) {
-    assert_cmd::Command::new(get_bin())
+    TestContext::new_command_with(&get_bin())
         .arg("venv")
         .arg(path.as_ref().as_os_str())
         .arg("--clear")