diff --git a/.changeset/kind-coins-serve.md b/.changeset/kind-coins-serve.md
new file mode 100644
index 0000000000..82a382bd5b
--- /dev/null
+++ b/.changeset/kind-coins-serve.md
@@ -0,0 +1,9 @@
+---
+"react-router": patch
+---
+
+Fix RSC double slashes in manifest URLs
+
+Normalize double slashes in getManifestUrl function to prevent ERR_NAME_NOT_RESOLVED errors when URLs contain double slashes like //en//test2/test
+
+
diff --git a/contributors.yml b/contributors.yml
index c1a62e6103..ab327719bd 100644
--- a/contributors.yml
+++ b/contributors.yml
@@ -459,3 +459,4 @@
 - zeromask1337
 - zheng-chuang
 - zxTomw
+- swarnim02
diff --git a/packages/react-router/__tests__/rsc-double-slashes-test.ts b/packages/react-router/__tests__/rsc-double-slashes-test.ts
new file mode 100644
index 0000000000..ab6f9ae9de
--- /dev/null
+++ b/packages/react-router/__tests__/rsc-double-slashes-test.ts
@@ -0,0 +1,20 @@
+import { joinPaths } from "../lib/router/utils";
+
+describe("joinPaths double slash normalization", () => {
+  it("normalizes double slashes in single path", () => {
+    expect(joinPaths(["//en//test2/test"])).toBe("/en/test2/test");
+    expect(joinPaths(["/app//base/"])).toBe("/app/base/");
+    expect(joinPaths(["///multiple///slashes"])).toBe("/multiple/slashes");
+  });
+
+  it("normalizes double slashes in multiple paths", () => {
+    expect(joinPaths(["//en//test1", "//fr//test2"])).toBe("/en/test1/fr/test2");
+    expect(joinPaths(["path//with//double", "slashes//here"])).toBe("path/with/double/slashes/here");
+  });
+
+  it("preserves normal paths", () => {
+    expect(joinPaths(["/normal/path"])).toBe("/normal/path");
+    expect(joinPaths(["path/without/leading/slash"])).toBe("path/without/leading/slash");
+    expect(joinPaths([""])).toBe("");
+  });
+});
\ No newline at end of file
diff --git a/packages/react-router/lib/router/utils.ts b/packages/react-router/lib/router/utils.ts
index f90aba951f..cb1015c60f 100644
--- a/packages/react-router/lib/router/utils.ts
+++ b/packages/react-router/lib/router/utils.ts
@@ -1777,8 +1777,12 @@ export function resolveTo(
   return path;
 }
 
-export const joinPaths = (paths: string[]): string =>
-  paths.join("/").replace(/\/\/+/g, "/");
+export const joinPaths = (paths: string[]): string => {
+  return paths
+    .map(path => path.replace(/\/\/+/g, "/")) // Normalize double slashes within each path
+    .join("/")
+    .replace(/\/\/+/g, "/"); // Normalize any double slashes created by joining
+};
 
 export const normalizePathname = (pathname: string): string =>
   pathname.replace(/\/+$/, "").replace(/^\/*/, "/");
diff --git a/packages/react-router/lib/rsc/browser.tsx b/packages/react-router/lib/rsc/browser.tsx
index 5046e28179..78bc7428bd 100644
--- a/packages/react-router/lib/rsc/browser.tsx
+++ b/packages/react-router/lib/rsc/browser.tsx
@@ -22,7 +22,7 @@ import type {
   DataStrategyFunctionArgs,
   RouterContextProvider,
 } from "../router/utils";
-import { ErrorResponseImpl, createContext } from "../router/utils";
+import { ErrorResponseImpl, createContext, joinPaths } from "../router/utils";
 import type {
   DecodedSingleFetchResults,
   FetchAndDecodeFunction,
@@ -972,7 +972,9 @@ function getManifestUrl(paths: string[]): URL | null {
   }
 
   if (paths.length === 1) {
-    return new URL(`${paths[0]}.manifest`, window.location.origin);
+    // Normalize double slashes in the single path
+    const normalizedPath = joinPaths([paths[0]]);
+    return new URL(`${normalizedPath}.manifest`, window.location.origin);
   }
 
   const globalVar = window as WindowWithRouterGlobals;
@@ -980,8 +982,12 @@ function getManifestUrl(paths: string[]): URL | null {
     /^\/|\/$/g,
     "",
   );
+  // Normalize double slashes in basename
+  basename = joinPaths([basename]);
   let url = new URL(`${basename}/.manifest`, window.location.origin);
-  url.searchParams.set("paths", paths.sort().join(","));
+  // Normalize double slashes in all paths before joining
+  const normalizedPaths = paths.map(path => joinPaths([path]));
+  url.searchParams.set("paths", normalizedPaths.sort().join(","));
 
   return url;
 }