diff --git a/docs/root/version_history/current.rst b/docs/root/version_history/current.rst
index e40673e38cef3..8fd722049a198 100644
--- a/docs/root/version_history/current.rst
+++ b/docs/root/version_history/current.rst
@@ -26,6 +26,7 @@ Removed Config or Runtime
 * http: removed ``envoy.reloadable_features.dont_add_content_length_for_bodiless_requests deprecation`` and legacy code paths.
 * http: removed ``envoy.reloadable_features.improved_stream_limit_handling`` and legacy code paths.
 * http: removed ``envoy.reloadable_features.return_502_for_upstream_protocol_errors``. Envoy will always return 502 code upon encountering upstream protocol error.
+* http: removed ``envoy.reloadable_features.treat_host_like_authority`` and legacy code paths.
 * http: removed ``envoy.reloadable_features.treat_upstream_connect_timeout_as_connect_failure`` and legacy code paths.
 
 New Features
diff --git a/source/common/http/header_utility.cc b/source/common/http/header_utility.cc
index 7c87f4af84999..5ec89d6228c60 100644
--- a/source/common/http/header_utility.cc
+++ b/source/common/http/header_utility.cc
@@ -377,8 +377,7 @@ bool HeaderUtility::isRemovableHeader(absl::string_view header) {
 
 bool HeaderUtility::isModifiableHeader(absl::string_view header) {
   return (header.empty() || header[0] != ':') &&
-         (!Runtime::runtimeFeatureEnabled("envoy.reloadable_features.treat_host_like_authority") ||
-          !absl::EqualsIgnoreCase(header, Headers::get().HostLegacy.get()));
+         !absl::EqualsIgnoreCase(header, Headers::get().HostLegacy.get());
 }
 
 HeaderUtility::HeaderValidationResult HeaderUtility::checkHeaderNameForUnderscores(
diff --git a/source/common/runtime/runtime_features.cc b/source/common/runtime/runtime_features.cc
index 2ad1a5373aa4d..6c364c96660ea 100644
--- a/source/common/runtime/runtime_features.cc
+++ b/source/common/runtime/runtime_features.cc
@@ -84,7 +84,6 @@ constexpr const char* runtime_features[] = {
     "envoy.reloadable_features.require_strict_1xx_and_204_response_headers",
     "envoy.reloadable_features.send_strict_1xx_and_204_response_headers",
     "envoy.reloadable_features.strip_port_from_connect",
-    "envoy.reloadable_features.treat_host_like_authority",
     "envoy.reloadable_features.udp_listener_updates_filter_chain_in_place",
     "envoy.reloadable_features.udp_per_event_loop_read_limit",
     "envoy.reloadable_features.unquote_log_string_values",
diff --git a/test/common/router/config_impl_test.cc b/test/common/router/config_impl_test.cc
index c540db9e123f2..8d7945bf5c248 100644
--- a/test/common/router/config_impl_test.cc
+++ b/test/common/router/config_impl_test.cc
@@ -1710,29 +1710,6 @@ TEST_F(RouteMatcherTest, TestRequestHeadersToAddNoHostOrPseudoHeader) {
   }
 }
 
-TEST_F(RouteMatcherTest, TestRequestHeadersToAddLegacyHostHeader) {
-  TestScopedRuntime scoped_runtime;
-  Runtime::LoaderSingleton::getExisting()->mergeValues(
-      {{"envoy.reloadable_features.treat_host_like_authority", "false"}});
-
-  const std::string yaml = R"EOF(
-virtual_hosts:
-  - name: www2
-    domains: ["*"]
-    request_headers_to_add:
-      - header:
-          key: "host"
-          value: vhost-www2
-        append: false
-)EOF";
-
-  NiceMock<Envoy::StreamInfo::MockStreamInfo> stream_info;
-
-  envoy::config::route::v3::RouteConfiguration route_config = parseRouteConfigurationFromYaml(yaml);
-
-  EXPECT_NO_THROW(TestConfigImpl config(route_config, factory_context_, true));
-}
-
 // Validate that we can't remove :-prefixed request headers.
 TEST_F(RouteMatcherTest, TestRequestHeadersToRemoveNoPseudoHeader) {
   for (const std::string& header :