diff --git a/.changeset/bright-experts-grab.md b/.changeset/bright-experts-grab.md
new file mode 100644
index 0000000000..c1cfbf2a42
--- /dev/null
+++ b/.changeset/bright-experts-grab.md
@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+Support project root directories without a `package.json` if it exists in a parent directory
diff --git a/.changeset/cold-seals-count.md b/.changeset/cold-seals-count.md
new file mode 100644
index 0000000000..90e188ca03
--- /dev/null
+++ b/.changeset/cold-seals-count.md
@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+When providing a custom Vite config path via the CLI `--config`/`-c` flag, default the project root directory to the directory containing the Vite config when not explicitly provided
diff --git a/.changeset/forty-ants-teach.md b/.changeset/forty-ants-teach.md
new file mode 100644
index 0000000000..4b5476cb2a
--- /dev/null
+++ b/.changeset/forty-ants-teach.md
@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+Ensure consistent project root directory resolution logic in CLI commands
diff --git a/packages/react-router-dev/cli/commands.ts b/packages/react-router-dev/cli/commands.ts
index 62005266eb..071c8068a3 100644
--- a/packages/react-router-dev/cli/commands.ts
+++ b/packages/react-router-dev/cli/commands.ts
@@ -17,13 +17,13 @@ import * as Typegen from "../typegen";
 import { preloadVite, getVite } from "../vite/vite";
 
 export async function routes(
-  reactRouterRoot?: string,
+  rootDirectory?: string,
   flags: {
     config?: string;
     json?: boolean;
   } = {}
 ): Promise<void> {
-  let rootDirectory = reactRouterRoot ?? process.cwd();
+  rootDirectory = resolveRootDirectory(rootDirectory, flags);
   let configResult = await loadConfig({ rootDirectory });
 
   if (!configResult.ok) {
@@ -39,9 +39,7 @@ export async function build(
   root?: string,
   options: ViteBuildOptions = {}
 ): Promise<void> {
-  if (!root) {
-    root = process.env.REACT_ROUTER_ROOT || process.cwd();
-  }
+  root = resolveRootDirectory(root, options);
 
   let { build } = await import("../vite/build");
   if (options.profile) {
@@ -54,12 +52,14 @@ export async function build(
   }
 }
 
-export async function dev(root: string, options: ViteDevOptions = {}) {
+export async function dev(root?: string, options: ViteDevOptions = {}) {
   let { dev } = await import("../vite/dev");
   if (options.profile) {
     await profiler.start();
   }
   exitHook(() => profiler.stop(console.info));
+
+  root = resolveRootDirectory(root, options);
   await dev(root, options);
 
   // keep `react-router dev` alive by waiting indefinitely
@@ -77,7 +77,7 @@ let conjunctionListFormat = new Intl.ListFormat("en", {
 
 export async function generateEntry(
   entry?: string,
-  reactRouterRoot?: string,
+  rootDirectory?: string,
   flags: {
     typescript?: boolean;
     config?: string;
@@ -85,12 +85,12 @@ export async function generateEntry(
 ) {
   // if no entry passed, attempt to create both
   if (!entry) {
-    await generateEntry("entry.client", reactRouterRoot, flags);
-    await generateEntry("entry.server", reactRouterRoot, flags);
+    await generateEntry("entry.client", rootDirectory, flags);
+    await generateEntry("entry.server", rootDirectory, flags);
     return;
   }
 
-  let rootDirectory = reactRouterRoot ?? process.cwd();
+  rootDirectory = resolveRootDirectory(rootDirectory, flags);
   let configResult = await loadConfig({ rootDirectory });
 
   if (!configResult.ok) {
@@ -162,6 +162,17 @@ export async function generateEntry(
   );
 }
 
+function resolveRootDirectory(root?: string, flags?: { config?: string }) {
+  if (root) {
+    return path.resolve(root);
+  }
+
+  return (
+    process.env.REACT_ROUTER_ROOT ||
+    (flags?.config ? path.dirname(path.resolve(flags.config)) : process.cwd())
+  );
+}
+
 async function checkForEntry(
   rootDirectory: string,
   appDirectory: string,
@@ -198,8 +209,14 @@ async function createClientEntry(
   return contents;
 }
 
-export async function typegen(root: string, flags: { watch: boolean }) {
-  root ??= process.cwd();
+export async function typegen(
+  root: string,
+  flags: {
+    watch?: boolean;
+    config?: string;
+  }
+) {
+  root = resolveRootDirectory(root, flags);
 
   if (flags.watch) {
     await preloadVite();
diff --git a/packages/react-router-dev/config/config.ts b/packages/react-router-dev/config/config.ts
index 999e19eec3..6eaf7dabe8 100644
--- a/packages/react-router-dev/config/config.ts
+++ b/packages/react-router-dev/config/config.ts
@@ -688,7 +688,20 @@ export async function resolveEntryFiles({
   let entryServerFile: string;
   let entryClientFile = userEntryClientFile || "entry.client.tsx";
 
-  let pkgJson = await PackageJson.load(rootDirectory);
+  let packageJsonPath = findEntry(rootDirectory, "package", {
+    extensions: [".json"],
+    absolute: true,
+    walkParents: true,
+  });
+
+  if (!packageJsonPath) {
+    throw new Error(
+      `Could not find package.json in ${rootDirectory} or any of its parent directories`
+    );
+  }
+
+  let packageJsonDirectory = path.dirname(packageJsonPath);
+  let pkgJson = await PackageJson.load(packageJsonDirectory);
   let deps = pkgJson.content.dependencies ?? {};
 
   if (userEntryServerFile) {
@@ -717,7 +730,7 @@ export async function resolveEntryFiles({
       let packageManager = detectPackageManager() ?? "npm";
 
       execSync(`${packageManager} install`, {
-        cwd: rootDirectory,
+        cwd: packageJsonDirectory,
         stdio: "inherit",
       });
     }
@@ -741,14 +754,34 @@ const entryExts = [".js", ".jsx", ".ts", ".tsx"];
 function findEntry(
   dir: string,
   basename: string,
-  options?: { absolute?: boolean }
+  options?: {
+    absolute?: boolean;
+    extensions?: string[];
+    walkParents?: boolean;
+  }
 ): string | undefined {
-  for (let ext of entryExts) {
-    let file = path.resolve(dir, basename + ext);
-    if (fs.existsSync(file)) {
-      return options?.absolute ?? false ? file : path.relative(dir, file);
+  let currentDir = path.resolve(dir);
+  let { root } = path.parse(currentDir);
+
+  while (true) {
+    for (let ext of options?.extensions ?? entryExts) {
+      let file = path.resolve(currentDir, basename + ext);
+      if (fs.existsSync(file)) {
+        return options?.absolute ?? false ? file : path.relative(dir, file);
+      }
+    }
+
+    if (!options?.walkParents) {
+      return undefined;
     }
-  }
 
-  return undefined;
+    let parentDir = path.dirname(currentDir);
+    // Break out when we've reached the root directory or we're about to get
+    // stuck in a loop where `path.dirname` keeps returning "/"
+    if (currentDir === root || parentDir === currentDir) {
+      return undefined;
+    }
+
+    currentDir = parentDir;
+  }
 }