diff --git a/.changeset/big-months-deliver.md b/.changeset/big-months-deliver.md
new file mode 100644
index 0000000000..1cf873beb1
--- /dev/null
+++ b/.changeset/big-months-deliver.md
@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Added `--since <ref>` flag for `repo build` command.`
diff --git a/packages/cli/src/commands/index.ts b/packages/cli/src/commands/index.ts
index d3baa37b3f..5cb02c82b4 100644
--- a/packages/cli/src/commands/index.ts
+++ b/packages/cli/src/commands/index.ts
@@ -41,6 +41,10 @@ export function registerRepoCommand(program: CommanderStatic) {
       '--all',
       'Build all packages, including bundled app and backend packages.',
     )
+    .option(
+      '--since <ref>',
+      'Only build packages and their dev dependents that changed since the specified ref',
+    )
     .action(lazy(() => import('./repo/build').then(m => m.command)));
 
   command
diff --git a/packages/cli/src/commands/repo/build.ts b/packages/cli/src/commands/repo/build.ts
index ceb468ebfa..fe50bee84f 100644
--- a/packages/cli/src/commands/repo/build.ts
+++ b/packages/cli/src/commands/repo/build.ts
@@ -78,7 +78,18 @@ function createScriptOptionsParser(anyCmd: Command, commandPath: string[]) {
 }
 
 export async function command(cmd: Command): Promise<void> {
-  const packages = await PackageGraph.listTargetPackages();
+  let packages = await PackageGraph.listTargetPackages();
+
+  if (cmd.since) {
+    const graph = PackageGraph.fromPackages(packages);
+    const changedPackages = await graph.listChangedPackages({ ref: cmd.since });
+    const withDevDependents = graph.collectPackageNames(
+      changedPackages.map(pkg => pkg.name),
+      pkg => pkg.localDevDependents.keys(),
+    );
+    packages = Array.from(withDevDependents).map(name => graph.get(name)!);
+  }
+
   const apps = new Array<ExtendedPackage>();
   const backends = new Array<ExtendedPackage>();
 
diff --git a/packages/cli/src/lib/monorepo/PackageGraph.test.ts b/packages/cli/src/lib/monorepo/PackageGraph.test.ts
index 06427a7313..feb1709bf7 100644
--- a/packages/cli/src/lib/monorepo/PackageGraph.test.ts
+++ b/packages/cli/src/lib/monorepo/PackageGraph.test.ts
@@ -87,6 +87,11 @@ describe('PackageGraph', () => {
       localDependencies: new Map([['b', b]]),
       localDevDependencies: new Map([['c', c]]),
       localOptionalDependencies: new Map(),
+      allLocalDependents: new Map(),
+      publishedLocalDependents: new Map(),
+      localDependents: new Map(),
+      localDevDependents: new Map(),
+      localOptionalDependents: new Map(),
     });
     expect(b).toMatchObject({
       name: 'b',
@@ -96,6 +101,11 @@ describe('PackageGraph', () => {
       localDependencies: new Map(),
       localDevDependencies: new Map([['c', c]]),
       localOptionalDependencies: new Map(),
+      allLocalDependents: new Map([['a', a]]),
+      publishedLocalDependents: new Map([['a', a]]),
+      localDependents: new Map([['a', a]]),
+      localDevDependents: new Map(),
+      localOptionalDependents: new Map(),
     });
     expect(c).toMatchObject({
       name: 'c',
@@ -105,6 +115,17 @@ describe('PackageGraph', () => {
       localDependencies: new Map(),
       localDevDependencies: new Map(),
       localOptionalDependencies: new Map(),
+      allLocalDependents: new Map([
+        ['a', a],
+        ['b', b],
+      ]),
+      publishedLocalDependents: new Map(),
+      localDependents: new Map(),
+      localDevDependents: new Map([
+        ['a', a],
+        ['b', b],
+      ]),
+      localOptionalDependents: new Map(),
     });
   });
 
diff --git a/packages/cli/src/lib/monorepo/PackageGraph.ts b/packages/cli/src/lib/monorepo/PackageGraph.ts
index 4bbb9eac67..c65f5c003c 100644
--- a/packages/cli/src/lib/monorepo/PackageGraph.ts
+++ b/packages/cli/src/lib/monorepo/PackageGraph.ts
@@ -47,6 +47,7 @@ export type PackageGraphNode = {
   dir: string;
   /** The package data of the package itself */
   packageJson: ExtendedPackageJSON;
+
   /** All direct local dependencies of the package */
   allLocalDependencies: Map<string, PackageGraphNode>;
   /** All direct local dependencies that will be present in the published package */
@@ -57,6 +58,17 @@ export type PackageGraphNode = {
   localDevDependencies: Map<string, PackageGraphNode>;
   /** Local optionalDependencies */
   localOptionalDependencies: Map<string, PackageGraphNode>;
+
+  /** All direct incoming local dependencies of the package */
+  allLocalDependents: Map<string, PackageGraphNode>;
+  /** All direct incoming local dependencies that will be present in the published package */
+  publishedLocalDependents: Map<string, PackageGraphNode>;
+  /** Incoming local dependencies */
+  localDependents: Map<string, PackageGraphNode>;
+  /** Incoming local devDependencies */
+  localDevDependents: Map<string, PackageGraphNode>;
+  /** Incoming local optionalDependencies */
+  localOptionalDependents: Map<string, PackageGraphNode>;
 };
 
 export class PackageGraph extends Map<string, PackageGraphNode> {
@@ -82,11 +94,18 @@ export class PackageGraph extends Map<string, PackageGraphNode> {
         name,
         dir: pkg.dir,
         packageJson: pkg.packageJson as ExtendedPackageJSON,
+
         allLocalDependencies: new Map(),
         publishedLocalDependencies: new Map(),
         localDependencies: new Map(),
         localDevDependencies: new Map(),
         localOptionalDependencies: new Map(),
+
+        allLocalDependents: new Map(),
+        publishedLocalDependents: new Map(),
+        localDependents: new Map(),
+        localDevDependents: new Map(),
+        localOptionalDependents: new Map(),
       });
     }
 
@@ -98,6 +117,10 @@ export class PackageGraph extends Map<string, PackageGraphNode> {
           node.allLocalDependencies.set(depName, depPkg);
           node.publishedLocalDependencies.set(depName, depPkg);
           node.localDependencies.set(depName, depPkg);
+
+          depPkg.allLocalDependents.set(node.name, node);
+          depPkg.publishedLocalDependents.set(node.name, node);
+          depPkg.localDependents.set(node.name, node);
         }
       }
       for (const depName of Object.keys(
@@ -107,6 +130,9 @@ export class PackageGraph extends Map<string, PackageGraphNode> {
         if (depPkg) {
           node.allLocalDependencies.set(depName, depPkg);
           node.localDevDependencies.set(depName, depPkg);
+
+          depPkg.allLocalDependents.set(node.name, node);
+          depPkg.localDevDependents.set(node.name, node);
         }
       }
       for (const depName of Object.keys(
@@ -117,6 +143,10 @@ export class PackageGraph extends Map<string, PackageGraphNode> {
           node.allLocalDependencies.set(depName, depPkg);
           node.publishedLocalDependencies.set(depName, depPkg);
           node.localOptionalDependencies.set(depName, depPkg);
+
+          depPkg.allLocalDependents.set(node.name, node);
+          depPkg.publishedLocalDependents.set(node.name, node);
+          depPkg.localOptionalDependents.set(node.name, node);
         }
       }
     }