diff --git a/tornado/curl_httpclient.py b/tornado/curl_httpclient.py
index 06c75fe30..41c8b8d93 100644
--- a/tornado/curl_httpclient.py
+++ b/tornado/curl_httpclient.py
@@ -441,7 +441,7 @@ def write_function(b: bytes | bytearray) -> int:
         else:
             raise KeyError("unknown method " + request.method)
 
-        body_expected = request.method in ("POST", "PATCH", "PUT")
+        body_expected = request.method in ("POST", "PATCH", "PUT", "QUERY")
         body_present = request.body is not None
         if not request.allow_nonstandard_methods:
             # Some HTTP methods nearly always have bodies while others
diff --git a/tornado/http1connection.py b/tornado/http1connection.py
index 17ada11f6..8c1fa6070 100644
--- a/tornado/http1connection.py
+++ b/tornado/http1connection.py
@@ -396,7 +396,7 @@ def write_headers(
             # Content-Length or a Transfer-Encoding. If Content-Length is not
             # present we'll add our Transfer-Encoding below.
             self._chunking_output = (
-                start_line.method in ("POST", "PUT", "PATCH")
+                start_line.method in ("POST", "PUT", "PATCH", "QUERY")
                 and "Content-Length" not in headers
             )
         else:
diff --git a/tornado/simple_httpclient.py b/tornado/simple_httpclient.py
index b8e4d8c93..dc9f1f71a 100644
--- a/tornado/simple_httpclient.py
+++ b/tornado/simple_httpclient.py
@@ -245,7 +245,16 @@ def _on_timeout(self, key: object, info: str | None = None) -> None:
 
 
 class _HTTPConnection(httputil.HTTPMessageDelegate):
-    _SUPPORTED_METHODS = {"GET", "HEAD", "POST", "PUT", "DELETE", "PATCH", "OPTIONS"}
+    _SUPPORTED_METHODS = {
+        "GET",
+        "HEAD",
+        "POST",
+        "PUT",
+        "DELETE",
+        "PATCH",
+        "OPTIONS",
+        "QUERY",
+    }
 
     def __init__(
         self,
@@ -399,7 +408,12 @@ async def run(self) -> None:
                 # Some HTTP methods nearly always have bodies while others
                 # almost never do. Fail in this case unless the user has
                 # opted out of sanity checks with allow_nonstandard_methods.
-                body_expected = self.request.method in ("POST", "PATCH", "PUT")
+                body_expected = self.request.method in (
+                    "POST",
+                    "PATCH",
+                    "PUT",
+                    "QUERY",
+                )
                 body_present = (
                     self.request.body is not None
                     or self.request.body_producer is not None
@@ -673,7 +687,8 @@ def finish(self) -> None:
             # for *all* methods, but libcurl < 7.70 only does this
             # for POST, while libcurl >= 7.70 does it for other methods.
             if (self.code == 303 and self.request.method != "HEAD") or (
-                self.code in (301, 302) and self.request.method == "POST"
+                self.code in (301, 302)
+                and self.request.method in ("POST", "QUERY")
             ):
                 new_request.method = "GET"
                 new_request.body = None  # type: ignore
diff --git a/tornado/test/httpclient_test.py b/tornado/test/httpclient_test.py
index 64e5cc5ff..8b6b1aff8 100644
--- a/tornado/test/httpclient_test.py
+++ b/tornado/test/httpclient_test.py
@@ -119,13 +119,13 @@ def patch(self):
 
 
 class AllMethodsHandler(RequestHandler):
-    SUPPORTED_METHODS = RequestHandler.SUPPORTED_METHODS + ("OTHER",)  # type: ignore
+    SUPPORTED_METHODS = RequestHandler.SUPPORTED_METHODS + ("OTHER", "QUERY")  # type: ignore
 
     def method(self):
         assert self.request.method is not None
         self.write(self.request.method)
 
-    get = head = post = put = delete = options = patch = other = method  # type: ignore
+    get = head = post = put = delete = options = patch = other = query = method  # type: ignore
 
 
 class SetHeaderHandler(RequestHandler):
@@ -385,6 +385,22 @@ def test_method_after_redirect(self):
             self.assertEqual(200, resp.code)
             self.assertEqual(b"", resp.body)
 
+    def test_query_after_redirect(self):
+        # QUERY is a safe, idempotent, cacheable method (RFC 10008) so
+        # a 301/302/303 redirect from a QUERY request should turn the
+        # followed request into a GET, matching the behaviour of
+        # browsers and what Tornado already does for POST.
+        for status in [301, 302, 303]:
+            url = "/redirect?url=/all_methods&status=%d" % status
+            resp = self.fetch(url, method="QUERY", body=b"id=42")
+            self.assertEqual(b"GET", resp.body)
+
+        # Newer redirects preserve the original QUERY method.
+        for status in [307, 308]:
+            url = "/redirect?url=/all_methods&status=%d" % status
+            resp = self.fetch(url, method="QUERY", body=b"id=42")
+            self.assertEqual(b"QUERY", resp.body)
+
     def test_credentials_in_url(self):
         url = self.get_url("/auth").replace("http://", "http://me:secret@")
         response = self.fetch(url)
diff --git a/tornado/test/web_test.py b/tornado/test/web_test.py
index 36049e26b..4ce29f02f 100644
--- a/tornado/test/web_test.py
+++ b/tornado/test/web_test.py
@@ -2337,6 +2337,35 @@ def test_other(self):
         self.assertEqual(response.body, b"other")
 
 
+class QueryMethodTest(SimpleHandlerTestCase):
+    """The QUERY method was standardised by RFC 10008. It is safe, idempotent
+    and cacheable, and carries its query in a request body rather than in
+    the URL. Tornado's RequestHandler should treat it like any other
+    standard method (responds with 405 when not implemented, dispatches to
+    ``query()`` when implemented).
+    """
+
+    class Handler(RequestHandler):
+        # Intentionally no ``query`` method. The default stub raises 405.
+        pass
+
+    def test_unimplemented_query(self):
+        # QUERY is now in SUPPORTED_METHODS by default, so the
+        # unimplemented-method stub should produce a 405.
+        response = self.fetch("/", method="QUERY", body=b"")
+        self.assertEqual(response.code, 405)
+
+
+class QueryMethodDispatchTest(SimpleHandlerTestCase):
+    class Handler(RequestHandler):
+        def query(self):
+            self.write("query")
+
+    def test_query(self):
+        response = self.fetch("/", method="QUERY", body=b"")
+        self.assertEqual(response.body, b"query")
+
+
 class FinishInPrepareTest(SimpleHandlerTestCase):
     class Handler(RequestHandler):
         def prepare(self):
diff --git a/tornado/web.py b/tornado/web.py
index b572beac0..1e4c0ffa9 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -180,6 +180,7 @@ class RequestHandler:
         "PATCH",
         "PUT",
         "OPTIONS",
+        "QUERY",
     )
 
     _template_loaders: dict[str, template.BaseLoader] = {}
@@ -263,6 +264,7 @@ def _unimplemented_method(self, *args: str, **kwargs: str) -> None:
     patch: Callable[..., Awaitable[None] | None] = _unimplemented_method
     put: Callable[..., Awaitable[None] | None] = _unimplemented_method
     options: Callable[..., Awaitable[None] | None] = _unimplemented_method
+    query: Callable[..., Awaitable[None] | None] = _unimplemented_method
 
     def prepare(self) -> Awaitable[None] | None:
         """Called at the beginning of a request before  `get`/`post`/etc.