diff --git a/crates/uv-python/src/installation.rs b/crates/uv-python/src/installation.rs
index 92995a6ab87c..11a15ff73bac 100644
--- a/crates/uv-python/src/installation.rs
+++ b/crates/uv-python/src/installation.rs
@@ -345,8 +345,14 @@ impl PartialOrd for PythonInstallationKey {
         Some(self.cmp(other))
     }
 }
+
 impl Ord for PythonInstallationKey {
     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.to_string().cmp(&other.to_string())
+        self.implementation
+            .cmp(&other.implementation)
+            .then_with(|| other.version().cmp(&self.version()))
+            .then_with(|| self.os.to_string().cmp(&other.os.to_string()))
+            .then_with(|| self.arch.to_string().cmp(&other.arch.to_string()))
+            .then_with(|| self.libc.to_string().cmp(&other.libc.to_string()))
     }
 }
diff --git a/crates/uv-python/src/managed.rs b/crates/uv-python/src/managed.rs
index db40b95ace2c..6e87c40b311c 100644
--- a/crates/uv-python/src/managed.rs
+++ b/crates/uv-python/src/managed.rs
@@ -1,6 +1,6 @@
 use core::fmt;
 use fs_err as fs;
-use std::collections::BTreeSet;
+use itertools::Itertools;
 use std::ffi::OsStr;
 use std::io::{self, Write};
 use std::path::{Path, PathBuf};
@@ -134,17 +134,15 @@ impl ManagedPythonInstallations {
 
     /// Iterate over each Python installation in this directory.
     ///
-    /// Pythons are sorted descending by name, such that we get deterministic
-    /// ordering across platforms. This also results in newer Python versions coming first,
-    /// but should not be relied on — instead the installations should be sorted later by
-    /// the parsed Python version.
+    /// Pythons are sorted by [`PythonInstallationKey`], for the same implementation name, the newest versions come first.
+    /// This ensures a consistent ordering across all platforms.
     pub fn find_all(
         &self,
     ) -> Result<impl DoubleEndedIterator<Item = ManagedPythonInstallation>, Error> {
         let dirs = match fs_err::read_dir(&self.root) {
             Ok(installation_dirs) => {
                 // Collect sorted directory paths; `read_dir` is not stable across platforms
-                let directories: BTreeSet<_> = installation_dirs
+                let directories: Vec<_> = installation_dirs
                     .filter_map(|read_dir| match read_dir {
                         Ok(entry) => match entry.file_type() {
                             Ok(file_type) => file_type.is_dir().then_some(Ok(entry.path())),
@@ -159,7 +157,7 @@ impl ManagedPythonInstallations {
                     })?;
                 directories
             }
-            Err(err) if err.kind() == std::io::ErrorKind::NotFound => BTreeSet::default(),
+            Err(err) if err.kind() == std::io::ErrorKind::NotFound => vec![],
             Err(err) => {
                 return Err(Error::ReadError {
                     dir: self.root.clone(),
@@ -176,7 +174,7 @@ impl ManagedPythonInstallations {
                     })
                     .ok()
             })
-            .rev())
+            .sorted_unstable_by_key(|installation| installation.key().clone()))
     }
 
     /// Iterate over Python installations that support the current platform.