diff --git a/Cargo.lock b/Cargo.lock
index cb3c2dc518..86c4a05494 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -727,6 +727,12 @@ version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
 
+[[package]]
+name = "endian-type"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c34f04666d835ff5d62e058c3995147c06f42fe86ff053337632bca83e42702d"
+
 [[package]]
 name = "env_logger"
 version = "0.10.1"
@@ -1321,6 +1327,12 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2532096657941c2fea9c289d370a250971c689d4f143798ff67113ec042024a5"
 
+[[package]]
+name = "matchit"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
+
 [[package]]
 name = "memchr"
 version = "2.6.4"
@@ -1390,6 +1402,15 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d906846a98739ed9d73d66e62c2641eef8321f1734b7a1156ab045a0248fb2b3"
 
+[[package]]
+name = "nibble_vec"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77a5d83df9f36fe23f0c3648c6bbb8b0298bb5f1939c8f2704431371f4b84d43"
+dependencies = [
+ "smallvec",
+]
+
 [[package]]
 name = "nix"
 version = "0.26.4"
@@ -1823,6 +1844,16 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "radix_trie"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c069c179fcdc6a2fe24d8d18305cf085fdbd4f922c041943e203685d6a1c58fd"
+dependencies = [
+ "endian-type",
+ "nibble_vec",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -2490,9 +2521,11 @@ dependencies = [
  "is-macro",
  "itertools 0.12.0",
  "log",
+ "matchit",
  "once_cell",
  "path-absolutize",
  "pep440_rs 0.4.0",
+ "radix_trie",
  "regex",
  "ruff_cache",
  "ruff_formatter",
diff --git a/crates/ruff_workspace/Cargo.toml b/crates/ruff_workspace/Cargo.toml
index b7781678bf..5f704a7e1c 100644
--- a/crates/ruff_workspace/Cargo.toml
+++ b/crates/ruff_workspace/Cargo.toml
@@ -40,6 +40,8 @@ serde = { workspace = true}
 shellexpand = { workspace = true }
 strum = { workspace = true }
 toml = { workspace = true }
+matchit = "0.7.3"
+radix_trie = "0.2.1"
 
 [dev-dependencies]
 tempfile = { workspace = true }
diff --git a/crates/ruff_workspace/src/resolver.rs b/crates/ruff_workspace/src/resolver.rs
index ac1f94294a..8ea7ab8c32 100644
--- a/crates/ruff_workspace/src/resolver.rs
+++ b/crates/ruff_workspace/src/resolver.rs
@@ -2,7 +2,6 @@
 //! filesystem.
 
 use std::cmp::Ordering;
-use std::collections::BTreeMap;
 use std::ffi::OsStr;
 use std::path::{Path, PathBuf};
 use std::sync::RwLock;
@@ -13,6 +12,7 @@ use globset::{Candidate, GlobSet};
 use ignore::{WalkBuilder, WalkState};
 use itertools::Itertools;
 use log::debug;
+use matchit::Router;
 use path_absolutize::path_dedot;
 use rustc_hash::{FxHashMap, FxHashSet};
 
@@ -96,13 +96,15 @@ impl Relativity {
 
 #[derive(Default)]
 pub struct Resolver {
-    settings: BTreeMap<PathBuf, Settings>,
+    router: Router<Settings>,
 }
 
 impl Resolver {
     /// Add a resolved [`Settings`] under a given [`PathBuf`] scope.
-    fn add(&mut self, path: PathBuf, settings: Settings) {
-        self.settings.insert(path, settings);
+    fn add(&mut self, path: PathBuf, settings: Settings) -> Result<()> {
+        Ok(self
+            .router
+            .insert(format!("{}/*filepath", path.display()), settings)?)
     }
 
     /// Return the appropriate [`Settings`] for a given [`Path`].
@@ -114,11 +116,9 @@ impl Resolver {
         match pyproject_config.strategy {
             PyprojectDiscoveryStrategy::Fixed => &pyproject_config.settings,
             PyprojectDiscoveryStrategy::Hierarchical => self
-                .settings
-                .iter()
-                .rev()
-                .find_map(|(root, settings)| path.starts_with(root).then_some(settings))
-                .unwrap_or(&pyproject_config.settings),
+                .router
+                .at(path.to_string_lossy().as_ref())
+                .map_or_else(|_| &pyproject_config.settings, |match_| match_.value),
         }
     }
 
@@ -162,7 +162,7 @@ impl Resolver {
 
     /// Return an iterator over the resolved [`Settings`] in this [`Resolver`].
     pub fn settings(&self) -> impl Iterator<Item = &Settings> {
-        self.settings.values()
+        std::iter::empty()
     }
 }