diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 197bada5808..24b384a5e64 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -15,6 +15,7 @@ This serves two purposes:
 
 ### Changed
 - The `docs.sidebar.footer` config option now accepts a Markdown string to replace the default footer in https://github.com/hydephp/develop/pull/1477
+- Links in the `sitemap.xml` file are now relative when a site URL is not set, instead of using the default localhost URL in https://github.com/hydephp/develop/pull/1479
 
 ### Deprecated
 - for soon-to-be removed features.
diff --git a/packages/framework/src/Framework/Features/XmlGenerators/SitemapGenerator.php b/packages/framework/src/Framework/Features/XmlGenerators/SitemapGenerator.php
index 64b5690c2c0..38e53a3aa3b 100644
--- a/packages/framework/src/Framework/Features/XmlGenerators/SitemapGenerator.php
+++ b/packages/framework/src/Framework/Features/XmlGenerators/SitemapGenerator.php
@@ -17,10 +17,12 @@
 use Hyde\Foundation\Facades\Routes;
 use Hyde\Framework\Concerns\TracksExecutionTime;
 
+use function blank;
 use function filemtime;
 use function in_array;
 use function date;
 use function time;
+use function str_starts_with;
 
 /**
  * @see https://www.sitemaps.org/protocol.html
@@ -57,7 +59,7 @@ protected function addRoute(Route $route): void
     {
         $urlItem = $this->xmlElement->addChild('url');
 
-        $this->addChild($urlItem, 'loc', Hyde::url($route->getOutputPath()));
+        $this->addChild($urlItem, 'loc', $this->resolveRouteLink($route));
         $this->addChild($urlItem, 'lastmod', $this->getLastModDate($route->getSourcePath()));
         $this->addChild($urlItem, 'changefreq', 'daily');
 
@@ -103,4 +105,18 @@ protected function getFormattedProcessingTime(): string
     {
         return (string) $this->getExecutionTimeInMs();
     }
+
+    protected function resolveRouteLink(Route $route): string
+    {
+        $baseUrl = Config::getNullableString('hyde.url');
+
+        if (blank($baseUrl) || str_starts_with($baseUrl, 'http://localhost')) {
+            // While the sitemap spec requires a full URL, we rather fall back
+            // to using relative links instead of using localhost links.
+
+            return $route->getLink();
+        } else {
+            return Hyde::url($route->getOutputPath());
+        }
+    }
 }
diff --git a/packages/framework/tests/Feature/Services/SitemapServiceTest.php b/packages/framework/tests/Feature/Services/SitemapServiceTest.php
index dddc5e42daa..e82342eb974 100644
--- a/packages/framework/tests/Feature/Services/SitemapServiceTest.php
+++ b/packages/framework/tests/Feature/Services/SitemapServiceTest.php
@@ -158,4 +158,26 @@ public function test_all_route_types_are_discovered()
         copy(Hyde::vendorPath('resources/views/homepages/welcome.blade.php'), Hyde::path('_pages/index.blade.php'));
         copy(Hyde::vendorPath('resources/views/pages/404.blade.php'), Hyde::path('_pages/404.blade.php'));
     }
+
+    public function testLinksFallbackToRelativeLinksWhenASiteUrlIsNotSet()
+    {
+        config(['hyde.url' => null]);
+
+        $service = new SitemapGenerator();
+        $service->generate();
+
+        $this->assertEquals('404.html', $service->getXmlElement()->url[0]->loc);
+        $this->assertEquals('index.html', $service->getXmlElement()->url[1]->loc);
+    }
+
+    public function testLinksFallbackToRelativeLinksWhenSiteUrlIsLocalhost()
+    {
+        config(['hyde.url' => 'http://localhost']);
+
+        $service = new SitemapGenerator();
+        $service->generate();
+
+        $this->assertEquals('404.html', $service->getXmlElement()->url[0]->loc);
+        $this->assertEquals('index.html', $service->getXmlElement()->url[1]->loc);
+    }
 }