diff --git a/.changeset/whole-geckos-think.md b/.changeset/whole-geckos-think.md
new file mode 100644
index 000000000000..c9f6d2487cc5
--- /dev/null
+++ b/.changeset/whole-geckos-think.md
@@ -0,0 +1,51 @@
+---
+'astro': major
+---
+
+Updates `<script>` and `<style>` tags to render in the order they are defined
+
+In Astro v5.5, the `experimental.preserveScriptOrder` flag was introduced to render multiple `<style>` and `<script>` tags in the same order as they were declared in the source code. Astro 5.x reversed their order in your generated HTML output. This could give unexpected results, for example, CSS styles being overridden by earlier defined style tags when your site was built.
+
+Astro 6.0 removes this experimental flag and makes this the new default behavior in Astro: scripts and styles are now rendered in the order defined in your code.
+
+#### What should I do?
+
+If you were previously using this experimental feature, you must remove this experimental flag from your configuration as it no longer exists:
+
+```diff
+// astro.config.mjs
+import { defineConfig } from 'astro/config';
+
+export default defineConfig({
+  experimental: {
+-    preserveScriptOrder: true,
+  },
+})
+```
+
+Review your `<script>` and `<style>` tags to make sure they behave as desired. You may need to reverse their order:
+
+```diff
+<!-- src/components/MyComponent.astro -->
+<p>I am a component</p>
+<style>
+  body {
+-    background: red;
++    background: yellow;
+  }
+</style>
+<style>
+  body {
+-    background: yellow;
++    background: red;
+  }
+</style>
+<script>
+-    console.log("hello")
++    console.log("world")
+</script>
+<script>
+-    console.log("world!")
++    console.log("hello!")
+</script>
+```
diff --git a/packages/astro/package.json b/packages/astro/package.json
index fa499f8b496a..c2949bfee431 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -106,7 +106,7 @@
     "test:integration": "astro-scripts test \"test/*.test.js\""
   },
   "dependencies": {
-    "@astrojs/compiler": "0.0.0-next-result-create-astro-20250926081949",
+    "@astrojs/compiler": "0.0.0-script-order-20251002140654",
     "@astrojs/internal-helpers": "workspace:*",
     "@astrojs/markdown-remark": "workspace:*",
     "@astrojs/telemetry": "workspace:*",
diff --git a/packages/astro/src/core/compile/compile.ts b/packages/astro/src/core/compile/compile.ts
index e3ade372851d..336eb210e182 100644
--- a/packages/astro/src/core/compile/compile.ts
+++ b/packages/astro/src/core/compile/compile.ts
@@ -62,7 +62,6 @@ export async function compile({
 				cssPartialCompileResults,
 				cssTransformErrors,
 			}),
-			experimentalScriptOrder: astroConfig.experimental.preserveScriptOrder ?? false,
 			async resolvePath(specifier) {
 				return resolvePath(specifier, filename);
 			},
diff --git a/packages/astro/src/core/config/schemas/base.ts b/packages/astro/src/core/config/schemas/base.ts
index ddba2f3f2ca6..b708001f55c7 100644
--- a/packages/astro/src/core/config/schemas/base.ts
+++ b/packages/astro/src/core/config/schemas/base.ts
@@ -97,7 +97,6 @@ export const ASTRO_CONFIG_DEFAULTS = {
 		clientPrerender: false,
 		contentIntellisense: false,
 		headingIdCompat: false,
-		preserveScriptOrder: false,
 		liveContentCollections: false,
 		csp: false,
 		staticImportMetaEnv: false,
@@ -468,10 +467,6 @@ export const AstroConfigSchema = z.object({
 				.boolean()
 				.optional()
 				.default(ASTRO_CONFIG_DEFAULTS.experimental.headingIdCompat),
-			preserveScriptOrder: z
-				.boolean()
-				.optional()
-				.default(ASTRO_CONFIG_DEFAULTS.experimental.preserveScriptOrder),
 			fonts: z.array(z.union([localFontFamilySchema, remoteFontFamilySchema])).optional(),
 			liveContentCollections: z
 				.boolean()
diff --git a/packages/astro/src/types/public/config.ts b/packages/astro/src/types/public/config.ts
index bd82172a645a..8c63821a2a43 100644
--- a/packages/astro/src/types/public/config.ts
+++ b/packages/astro/src/types/public/config.ts
@@ -2358,48 +2358,6 @@ export interface ViteUserConfig extends OriginalViteUserConfig {
 					directives?: CspDirective[];
 			  };
 
-		/**
-		 * @name experimental.preserveScriptOrder
-		 * @type {boolean}
-		 * @default `false`
-		 * @version 5.5
-		 * @description
-		 *
-		 * When enabled, `<script>` and `<style>` tags are rendered in the same order as they are defined.
-		 *
-		 * ## Example
-		 *
-		 * Consider the following component:
-		 *
-		 * ```html
-		 * <p>I am a component</p>
-		 * <style>
-		 *   body {
-		 *     background: red;
-		 *   }
-		 * </style>
-		 * <style>
-		 *   body {
-		 *     background: yellow;
-		 *   }
-		 * </style>
-		 * ```
-		 *
-		 * By default, it will generate a CSS style where `red` will be applied:
-		 *
-		 * ```css
-		 * body {background:#ff0} body {background:red}
-		 * ```
-		 *
-		 * When this new option is set to `true`, the generated CSS style will apply `yellow`:
-		 *
-		 * ```css
-		 * body {background:red} body {background:#ff0}
-		 * ```
-		 *
-		 */
-		preserveScriptOrder?: boolean;
-
 		/**
 		 * @name experimental.liveContentCollections
 		 * @type {boolean}
diff --git a/packages/astro/test/astro-directives.test.js b/packages/astro/test/astro-directives.test.js
index 21feee339403..f33cab3d4b5b 100644
--- a/packages/astro/test/astro-directives.test.js
+++ b/packages/astro/test/astro-directives.test.js
@@ -70,7 +70,7 @@ describe('Directives', async () => {
 			$('#compound-style')
 				.attr('style')
 				.toString()
-				.includes('color:var(--fg);--fg: black;--bg: white;'),
+				.includes('color:var(--fg);--bg: white;--fg: black;'),
 			true,
 		);
 	});
diff --git a/packages/astro/test/fixtures/css-order-transparent/astro.config.mjs b/packages/astro/test/fixtures/css-order-transparent/astro.config.mjs
index 5ce5a4089f86..86dbfb924824 100644
--- a/packages/astro/test/fixtures/css-order-transparent/astro.config.mjs
+++ b/packages/astro/test/fixtures/css-order-transparent/astro.config.mjs
@@ -1,7 +1,3 @@
 import { defineConfig } from 'astro/config';
 
-export default defineConfig({
-	experimental: {
-		preserveScriptOrder: true,
-	}
-});
+export default defineConfig({});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 679e50a26b75..75008c93272d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -471,8 +471,8 @@ importers:
   packages/astro:
     dependencies:
       '@astrojs/compiler':
-        specifier: 0.0.0-next-result-create-astro-20250926081949
-        version: 0.0.0-next-result-create-astro-20250926081949
+        specifier: 0.0.0-script-order-20251002140654
+        version: 0.0.0-script-order-20251002140654
       '@astrojs/internal-helpers':
         specifier: workspace:*
         version: link:../internal-helpers
@@ -6498,8 +6498,8 @@ packages:
     resolution: {integrity: sha512-bVzyKzEpIwqjihBU/aUzt1LQckJuHK0agd3/ITdXhPUYculrc6K1/K7H+XG4rwjXtg+ikT3PM05V1MVYWiIvQw==}
     engines: {node: '>=18.14.1'}
 
-  '@astrojs/compiler@0.0.0-next-result-create-astro-20250926081949':
-    resolution: {integrity: sha512-iZAPYDe2R9fU1GA26epcy4iOvDgla3oWirzqOsc3nkKeSTcUYtY1rZq/D02oKCVHepAkFlRS1bS27+G+jIeX0Q==}
+  '@astrojs/compiler@0.0.0-script-order-20251002140654':
+    resolution: {integrity: sha512-6pR3ODwtdJt4wx+W8i0YUVIRonDu6+MILh25wALbcxhDlKDBt55iCQjwu7JLbDg6eln2CvscHvecTKu/uBnlWA==}
 
   '@astrojs/compiler@2.12.2':
     resolution: {integrity: sha512-w2zfvhjNCkNMmMMOn5b0J8+OmUaBL1o40ipMvqcG6NRpdC+lKxmTi48DT8Xw0SzJ3AfmeFLB45zXZXtmbsjcgw==}
@@ -14256,7 +14256,7 @@ snapshots:
       log-update: 5.0.1
       sisteransi: 1.0.5
 
-  '@astrojs/compiler@0.0.0-next-result-create-astro-20250926081949': {}
+  '@astrojs/compiler@0.0.0-script-order-20251002140654': {}
 
   '@astrojs/compiler@2.12.2': {}