diff --git a/src/apprt/glfw.zig b/src/apprt/glfw.zig
index e793615d5..bf4c44ad0 100644
--- a/src/apprt/glfw.zig
+++ b/src/apprt/glfw.zig
@@ -724,7 +724,7 @@ pub const Surface = struct {
     /// Set the shape of the cursor.
     fn setMouseShape(self: *Surface, shape: terminal.MouseShape) !void {
         if ((comptime builtin.target.isDarwin()) and
-            !internal_os.macosVersionAtLeast(13, 0, 0))
+            !internal_os.macos.isAtLeastVersion(13, 0, 0))
         {
             // We only set our cursor if we're NOT on Mac, or if we are then the
             // macOS version is >= 13 (Ventura). On prior versions, glfw crashes
diff --git a/src/apprt/gtk/App.zig b/src/apprt/gtk/App.zig
index bb5309333..6069c825d 100644
--- a/src/apprt/gtk/App.zig
+++ b/src/apprt/gtk/App.zig
@@ -14,6 +14,7 @@ const std = @import("std");
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const builtin = @import("builtin");
+const build_config = @import("../../build_config.zig");
 const apprt = @import("../../apprt.zig");
 const configpkg = @import("../../config.zig");
 const input = @import("../../input.zig");
@@ -181,7 +182,7 @@ pub fn init(core_app: *CoreApp, opts: Options) !App {
             }
         }
 
-        const default_id = "com.mitchellh.ghostty";
+        const default_id = comptime build_config.bundle_id;
         break :app_id if (builtin.mode == .Debug) default_id ++ "-debug" else default_id;
     };
 
diff --git a/src/apprt/gtk/ConfigErrorsWindow.zig b/src/apprt/gtk/ConfigErrorsWindow.zig
index 6d4cda21b..3ff52908e 100644
--- a/src/apprt/gtk/ConfigErrorsWindow.zig
+++ b/src/apprt/gtk/ConfigErrorsWindow.zig
@@ -3,6 +3,7 @@ const ConfigErrors = @This();
 
 const std = @import("std");
 const Allocator = std.mem.Allocator;
+const build_config = @import("../../build_config.zig");
 const configpkg = @import("../../config.zig");
 const Config = configpkg.Config;
 
@@ -53,7 +54,7 @@ fn init(self: *ConfigErrors, app: *App) !void {
     c.gtk_window_set_title(gtk_window, "Configuration Errors");
     c.gtk_window_set_default_size(gtk_window, 600, 275);
     c.gtk_window_set_resizable(gtk_window, 0);
-    c.gtk_window_set_icon_name(gtk_window, "com.mitchellh.ghostty");
+    c.gtk_window_set_icon_name(gtk_window, build_config.bundle_id);
     _ = c.g_signal_connect_data(window, "destroy", c.G_CALLBACK(&gtkDestroy), self, null, c.G_CONNECT_DEFAULT);
 
     // Set some state
diff --git a/src/apprt/gtk/Surface.zig b/src/apprt/gtk/Surface.zig
index aef67b308..9a361c228 100644
--- a/src/apprt/gtk/Surface.zig
+++ b/src/apprt/gtk/Surface.zig
@@ -5,6 +5,7 @@ const Surface = @This();
 
 const std = @import("std");
 const Allocator = std.mem.Allocator;
+const build_config = @import("../../build_config.zig");
 const configpkg = @import("../../config.zig");
 const apprt = @import("../../apprt.zig");
 const font = @import("../../font/main.zig");
@@ -1149,7 +1150,7 @@ pub fn showDesktopNotification(
     defer c.g_object_unref(notification);
     c.g_notification_set_body(notification, body.ptr);
 
-    const icon = c.g_themed_icon_new("com.mitchellh.ghostty");
+    const icon = c.g_themed_icon_new(build_config.bundle_id);
     defer c.g_object_unref(icon);
     c.g_notification_set_icon(notification, icon);
 
diff --git a/src/apprt/gtk/Window.zig b/src/apprt/gtk/Window.zig
index e220ac03b..23265c101 100644
--- a/src/apprt/gtk/Window.zig
+++ b/src/apprt/gtk/Window.zig
@@ -103,7 +103,7 @@ pub fn init(self: *Window, app: *App) !void {
     // to disable this so that terminal programs can capture F10 (such as htop)
     c.gtk_window_set_handle_menubar_accel(gtk_window, 0);
 
-    c.gtk_window_set_icon_name(gtk_window, "com.mitchellh.ghostty");
+    c.gtk_window_set_icon_name(gtk_window, build_config.bundle_id);
 
     // Apply class to color headerbar if window-theme is set to `ghostty` and
     // GTK version is before 4.16. The conditional is because above 4.16
diff --git a/src/apprt/gtk/inspector.zig b/src/apprt/gtk/inspector.zig
index f5bdf8a24..119e20a6c 100644
--- a/src/apprt/gtk/inspector.zig
+++ b/src/apprt/gtk/inspector.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
 
+const build_config = @import("../../build_config.zig");
 const App = @import("App.zig");
 const Surface = @import("Surface.zig");
 const TerminalWindow = @import("Window.zig");
@@ -141,7 +142,7 @@ const Window = struct {
         self.window = gtk_window;
         c.gtk_window_set_title(gtk_window, "Ghostty: Terminal Inspector");
         c.gtk_window_set_default_size(gtk_window, 1000, 600);
-        c.gtk_window_set_icon_name(gtk_window, "com.mitchellh.ghostty");
+        c.gtk_window_set_icon_name(gtk_window, build_config.bundle_id);
 
         // Initialize our imgui widget
         try self.imgui_widget.init();
diff --git a/src/build_config.zig b/src/build_config.zig
index 715552e03..1448f9de5 100644
--- a/src/build_config.zig
+++ b/src/build_config.zig
@@ -103,6 +103,20 @@ pub const app_runtime: apprt.Runtime = config.app_runtime;
 pub const font_backend: font.Backend = config.font_backend;
 pub const renderer: rendererpkg.Impl = config.renderer;
 
+/// The bundle ID for the app. This is used in many places and is currently
+/// hardcoded here. We could make this configurable in the future if there
+/// is a reason to do so.
+///
+/// On macOS, this must match the App bundle ID. We can get that dynamically
+/// via an API but I don't want to pay the cost of that at runtime.
+///
+/// On GTK, this should match the various folders with resources.
+///
+/// There are many places that don't use this variable so simply swapping
+/// this variable is NOT ENOUGH to change the bundle ID. I just wanted to
+/// avoid it in Zig coe as much as possible.
+pub const bundle_id = "com.mitchellh.ghostty";
+
 /// True if we should have "slow" runtime safety checks. The initial motivation
 /// for this was terminal page/pagelist integrity checks. These were VERY
 /// slow but very thorough. But they made it so slow that the terminal couldn't
diff --git a/src/config/Config.zig b/src/config/Config.zig
index 0f8be9662..253e96420 100644
--- a/src/config/Config.zig
+++ b/src/config/Config.zig
@@ -1813,9 +1813,10 @@ pub fn deinit(self: *Config) void {
 /// Load the configuration according to the default rules:
 ///
 ///   1. Defaults
-///   2. XDG Config File
-///   3. CLI flags
-///   4. Recursively defined configuration files
+///   2. XDG config dir
+///   3. "Application Support" directory (macOS only)
+///   4. CLI flags
+///   5. Recursively defined configuration files
 ///
 pub fn load(alloc_gpa: Allocator) !Config {
     var result = try default(alloc_gpa);
@@ -2398,25 +2399,37 @@ pub fn loadFile(self: *Config, alloc: Allocator, path: []const u8) !void {
     try self.expandPaths(std.fs.path.dirname(path).?);
 }
 
-/// Load the configuration from the default configuration file. The default
-/// configuration file is at `$XDG_CONFIG_HOME/ghostty/config`.
-pub fn loadDefaultFiles(self: *Config, alloc: Allocator) !void {
-    const config_path = try internal_os.xdg.config(alloc, .{ .subdir = "ghostty/config" });
-    defer alloc.free(config_path);
-
-    self.loadFile(alloc, config_path) catch |err| switch (err) {
+/// Load optional configuration file from `path`. All errors are ignored.
+pub fn loadOptionalFile(self: *Config, alloc: Allocator, path: []const u8) void {
+    self.loadFile(alloc, path) catch |err| switch (err) {
         error.FileNotFound => std.log.info(
-            "homedir config not found, not loading path={s}",
-            .{config_path},
+            "optional config file not found, not loading path={s}",
+            .{path},
         ),
-
         else => std.log.warn(
-            "error reading config file, not loading err={} path={s}",
-            .{ err, config_path },
+            "error reading optional config file, not loading err={} path={s}",
+            .{ err, path },
         ),
     };
 }
 
+/// Load configurations from the default configuration files. The default
+/// configuration file is at `$XDG_CONFIG_HOME/ghostty/config`.
+///
+/// On macOS, `$HOME/Library/Application Support/$CFBundleIdentifier/config`
+/// is also loaded.
+pub fn loadDefaultFiles(self: *Config, alloc: Allocator) !void {
+    const xdg_path = try internal_os.xdg.config(alloc, .{ .subdir = "ghostty/config" });
+    defer alloc.free(xdg_path);
+    self.loadOptionalFile(alloc, xdg_path);
+
+    if (comptime builtin.os.tag == .macos) {
+        const app_support_path = try internal_os.macos.appSupportDir(alloc, "config");
+        defer alloc.free(app_support_path);
+        self.loadOptionalFile(alloc, app_support_path);
+    }
+}
+
 /// Load and parse the CLI args.
 pub fn loadCliArgs(self: *Config, alloc_gpa: Allocator) !void {
     switch (builtin.os.tag) {
diff --git a/src/main_ghostty.zig b/src/main_ghostty.zig
index 071d4d530..b3df80538 100644
--- a/src/main_ghostty.zig
+++ b/src/main_ghostty.zig
@@ -141,7 +141,7 @@ fn logFn(
 
         // Initialize a logger. This is slow to do on every operation
         // but we shouldn't be logging too much.
-        const logger = macos.os.Log.create("com.mitchellh.ghostty", @tagName(scope));
+        const logger = macos.os.Log.create(build_config.bundle_id, @tagName(scope));
         defer logger.release();
         logger.log(std.heap.c_allocator, mac_level, format, args);
     }
diff --git a/src/os/macos.zig b/src/os/macos.zig
new file mode 100644
index 000000000..d405cd161
--- /dev/null
+++ b/src/os/macos.zig
@@ -0,0 +1,77 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const build_config = @import("../build_config.zig");
+const assert = std.debug.assert;
+const objc = @import("objc");
+const Allocator = std.mem.Allocator;
+
+/// Verifies that the running macOS system version is at least the given version.
+pub fn isAtLeastVersion(major: i64, minor: i64, patch: i64) bool {
+    comptime assert(builtin.target.isDarwin());
+
+    const NSProcessInfo = objc.getClass("NSProcessInfo").?;
+    const info = NSProcessInfo.msgSend(objc.Object, objc.sel("processInfo"), .{});
+    return info.msgSend(bool, objc.sel("isOperatingSystemAtLeastVersion:"), .{
+        NSOperatingSystemVersion{ .major = major, .minor = minor, .patch = patch },
+    });
+}
+
+pub const AppSupportDirError = Allocator.Error || error{AppleAPIFailed};
+
+/// Return the path to the application support directory for Ghostty
+/// with the given sub path joined. This allocates the result using the
+/// given allocator.
+pub fn appSupportDir(
+    alloc: Allocator,
+    sub_path: []const u8,
+) AppSupportDirError![]u8 {
+    comptime assert(builtin.target.isDarwin());
+
+    const NSFileManager = objc.getClass("NSFileManager").?;
+    const manager = NSFileManager.msgSend(
+        objc.Object,
+        objc.sel("defaultManager"),
+        .{},
+    );
+
+    const url = manager.msgSend(
+        objc.Object,
+        objc.sel("URLForDirectory:inDomain:appropriateForURL:create:error:"),
+        .{
+            NSSearchPathDirectory.NSApplicationSupportDirectory,
+            NSSearchPathDomainMask.NSUserDomainMask,
+            @as(?*anyopaque, null),
+            true,
+            @as(?*anyopaque, null),
+        },
+    );
+
+    // I don't think this is possible but just in case.
+    if (url.value == null) return error.AppleAPIFailed;
+
+    // Get the UTF-8 string from the URL.
+    const path = url.getProperty(objc.Object, "path");
+    const c_str = path.getProperty(?[*:0]const u8, "UTF8String") orelse
+        return error.AppleAPIFailed;
+    const app_support_dir = std.mem.sliceTo(c_str, 0);
+
+    return try std.fs.path.join(alloc, &.{
+        app_support_dir,
+        build_config.bundle_id,
+        sub_path,
+    });
+}
+
+pub const NSOperatingSystemVersion = extern struct {
+    major: i64,
+    minor: i64,
+    patch: i64,
+};
+
+pub const NSSearchPathDirectory = enum(c_ulong) {
+    NSApplicationSupportDirectory = 14,
+};
+
+pub const NSSearchPathDomainMask = enum(c_ulong) {
+    NSUserDomainMask = 1,
+};
diff --git a/src/os/macos_version.zig b/src/os/macos_version.zig
deleted file mode 100644
index e0b21560e..000000000
--- a/src/os/macos_version.zig
+++ /dev/null
@@ -1,21 +0,0 @@
-const std = @import("std");
-const builtin = @import("builtin");
-const assert = std.debug.assert;
-const objc = @import("objc");
-
-/// Verifies that the running macOS system version is at least the given version.
-pub fn macosVersionAtLeast(major: i64, minor: i64, patch: i64) bool {
-    assert(builtin.target.isDarwin());
-
-    const NSProcessInfo = objc.getClass("NSProcessInfo").?;
-    const info = NSProcessInfo.msgSend(objc.Object, objc.sel("processInfo"), .{});
-    return info.msgSend(bool, objc.sel("isOperatingSystemAtLeastVersion:"), .{
-        NSOperatingSystemVersion{ .major = major, .minor = minor, .patch = patch },
-    });
-}
-
-pub const NSOperatingSystemVersion = extern struct {
-    major: i64,
-    minor: i64,
-    patch: i64,
-};
diff --git a/src/os/main.zig b/src/os/main.zig
index 22765f546..073129300 100644
--- a/src/os/main.zig
+++ b/src/os/main.zig
@@ -8,7 +8,6 @@ const file = @import("file.zig");
 const flatpak = @import("flatpak.zig");
 const homedir = @import("homedir.zig");
 const locale = @import("locale.zig");
-const macos_version = @import("macos_version.zig");
 const mouse = @import("mouse.zig");
 const openpkg = @import("open.zig");
 const pipepkg = @import("pipe.zig");
@@ -21,6 +20,7 @@ pub const hostname = @import("hostname.zig");
 pub const passwd = @import("passwd.zig");
 pub const xdg = @import("xdg.zig");
 pub const windows = @import("windows.zig");
+pub const macos = @import("macos.zig");
 
 // Functions and types
 pub const CFReleaseThread = @import("cf_release_thread.zig");
@@ -37,7 +37,6 @@ pub const freeTmpDir = file.freeTmpDir;
 pub const isFlatpak = flatpak.isFlatpak;
 pub const home = homedir.home;
 pub const ensureLocale = locale.ensureLocale;
-pub const macosVersionAtLeast = macos_version.macosVersionAtLeast;
 pub const clickInterval = mouse.clickInterval;
 pub const open = openpkg.open;
 pub const pipe = pipepkg.pipe;