diff --git a/changelog_unreleased/html/12882.md b/changelog_unreleased/html/12882.md
new file mode 100644
index 000000000..3e94364b6
--- /dev/null
+++ b/changelog_unreleased/html/12882.md
@@ -0,0 +1,32 @@
+#### Support Speculation Rules API formatting in HTML (#12882 by @sosukesuzuki)
+
+Please read https://web.dev/speculative-prerendering/ for about Speculation Rules API.
+
+<!-- prettier-ignore -->
+```html
+<!-- Input -->
+<script type="speculationrules">
+  {
+   "prerender": [
+  {"source": "list", "urls": ["https://a.test/foo"]}
+  ]
+  }
+</script>
+
+
+<!-- Prettier stable -->
+<script type="speculationrules">
+  {
+   "prerender": [
+  {"source": "list", "urls": ["https://a.test/foo"]}
+  ]
+  }
+</script>
+
+<!-- Prettier main -->
+<script type="speculationrules">
+  {
+    "prerender": [{ "source": "list", "urls": ["https://a.test/foo"] }]
+  }
+</script>
+```
diff --git a/cspell.json b/cspell.json
index 7c8802db1..6e12e2740 100644
--- a/cspell.json
+++ b/cspell.json
@@ -304,6 +304,7 @@
         "softlines",
         "Sorin",
         "Sosuke",
+        "speculationrules",
         "srcset",
         "Stachowiak",
         "standalones",
diff --git a/src/language-html/utils/index.js b/src/language-html/utils/index.js
index 20261d1e9..00b1e2412 100644
--- a/src/language-html/utils/index.js
+++ b/src/language-html/utils/index.js
@@ -364,7 +364,10 @@ function _inferScriptParser(node) {
     return "html";
   }
 
-  if (type && (type.endsWith("json") || type.endsWith("importmap"))) {
+  if (
+    (type && (type.endsWith("json") || type.endsWith("importmap"))) ||
+    type === "speculationrules"
+  ) {
     return "json";
   }
 
diff --git a/tests/format/html/script/__snapshots__/jsfmt.spec.js.snap b/tests/format/html/script/__snapshots__/jsfmt.spec.js.snap
index 52ec843f5..ce92e69e4 100644
--- a/tests/format/html/script/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/format/html/script/__snapshots__/jsfmt.spec.js.snap
@@ -171,6 +171,15 @@ End Function
 
 <script lang="unknown">
 </script>
+
+<script type="speculationrules">
+  {
+   "prerender": [
+  {"source": "list", "urls": ["https://a.test/foo"]}
+  ]
+  }
+  </script>
+
 =====================================output=====================================
 <script type="application/ld+json">
   { "json": true }
@@ -208,5 +217,11 @@ End Function
 
 <script lang="unknown"></script>
 
+<script type="speculationrules">
+  {
+    "prerender": [{ "source": "list", "urls": ["https://a.test/foo"] }]
+  }
+</script>
+
 ================================================================================
 `;
diff --git a/tests/format/html/script/script.html b/tests/format/html/script/script.html
index 67b16cd88..eff326ee5 100644
--- a/tests/format/html/script/script.html
+++ b/tests/format/html/script/script.html
@@ -31,4 +31,12 @@ End Function
 </script>
 
 <script lang="unknown">
-</script>
\ No newline at end of file
+</script>
+
+<script type="speculationrules">
+  {
+   "prerender": [
+  {"source": "list", "urls": ["https://a.test/foo"]}
+  ]
+  }
+  </script>