diff --git a/.changeset/fuzzy-cobras-unite.md b/.changeset/fuzzy-cobras-unite.md
new file mode 100644
index 00000000..d5ba72ae
--- /dev/null
+++ b/.changeset/fuzzy-cobras-unite.md
@@ -0,0 +1,5 @@
+---
+'@sigstore/tuf': patch
+---
+
+Include a custom User-Agent header with fetch calls made to TUF repository
diff --git a/package-lock.json b/package-lock.json
index 95387655..eab94eda 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1081,7 +1081,6 @@
       "integrity": "sha512-e7jT4DxYvIDLk1ZHmU/m/mB19rex9sv0c2ftBtjSBv+kVM/902eh0fINUzD7UwLLNR+jU585GxUJ8/EBfAM5fw==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@babel/code-frame": "^7.27.1",
         "@babel/generator": "^7.28.5",
@@ -5295,6 +5294,7 @@
       "os": [
         "darwin"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5312,6 +5312,7 @@
       "os": [
         "darwin"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5329,6 +5330,7 @@
       "os": [
         "linux"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5346,6 +5348,7 @@
       "os": [
         "linux"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5363,6 +5366,7 @@
       "os": [
         "linux"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5380,6 +5384,7 @@
       "os": [
         "linux"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5397,6 +5402,7 @@
       "os": [
         "linux"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5414,6 +5420,7 @@
       "os": [
         "win32"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5431,6 +5438,7 @@
       "os": [
         "win32"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5448,6 +5456,7 @@
       "os": [
         "win32"
       ],
+      "peer": true,
       "engines": {
         "node": ">=10"
       }
@@ -5479,6 +5488,7 @@
       "version": "0.1.6",
       "dev": true,
       "license": "Apache-2.0",
+      "peer": true,
       "dependencies": {
         "@swc/counter": "^0.1.3"
       }
@@ -5760,7 +5770,6 @@
       "integrity": "sha512-WOhQTZ4G8xZ1tjJTvKOpyEVSGgOTvJAfDK3FNFgELyaTpzhdgHVHeqW8V+UJvzF5BT+/B54T/1S2K6gd9c7bbA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "undici-types": "~7.16.0"
       }
@@ -5905,7 +5914,6 @@
       "integrity": "sha512-N9lBGA9o9aqb1hVMc9hzySbhKibHmB+N3IpoShyV6HyQYRGIhlrO5rQgttypi+yEeKsKI4idxC8Jw6gXKD4THA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@typescript-eslint/scope-manager": "8.49.0",
         "@typescript-eslint/types": "8.49.0",
@@ -6420,7 +6428,6 @@
       "integrity": "sha512-NZyJarBfL7nWwIq+FDL6Zp/yHEhePMNnnJ0y3qfieCrmNvYct8uvtiV41UvlSe6apAfk0fY1FbWx+NwfmpvtTg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "bin": {
         "acorn": "bin/acorn"
       },
@@ -6811,7 +6818,6 @@
         }
       ],
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "baseline-browser-mapping": "^2.8.19",
         "caniuse-lite": "^1.0.30001751",
@@ -7784,7 +7790,6 @@
       "integrity": "sha512-LEyamqS7W5HB3ujJyvi0HQK/dtVINZvd5mAAp9eT5S/ujByGjiZLCzPcHVzuXbpJDJF/cxwHlfceVUDZ2lnSTw==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@eslint-community/eslint-utils": "^4.8.0",
         "@eslint-community/regexpp": "^4.12.1",
@@ -12620,7 +12625,6 @@
       "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.3.tgz",
       "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -12739,19 +12743,47 @@
       "license": "0BSD"
     },
     "node_modules/tuf-js": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/tuf-js/-/tuf-js-4.0.0.tgz",
-      "integrity": "sha512-Lq7ieeGvXDXwpoSmOSgLWVdsGGV9J4a77oDTAPe/Ltrqnnm/ETaRlBAQTH5JatEh8KXuE6sddf9qAv1Q2282Hg==",
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/tuf-js/-/tuf-js-4.1.0.tgz",
+      "integrity": "sha512-50QV99kCKH5P/Vs4E2Gzp7BopNV+KzTXqWeaxrfu5IQJBOULRsTIS9seSsOVT8ZnGXzCyx55nYWAi4qJzpZKEQ==",
       "license": "MIT",
       "dependencies": {
-        "@tufjs/models": "4.0.0",
-        "debug": "^4.4.1",
-        "make-fetch-happen": "^15.0.0"
+        "@tufjs/models": "4.1.0",
+        "debug": "^4.4.3",
+        "make-fetch-happen": "^15.0.1"
+      },
+      "engines": {
+        "node": "^20.17.0 || >=22.9.0"
+      }
+    },
+    "node_modules/tuf-js/node_modules/@tufjs/models": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/@tufjs/models/-/models-4.1.0.tgz",
+      "integrity": "sha512-Y8cK9aggNRsqJVaKUlEYs4s7CvQ1b1ta2DVPyAimb0I2qhzjNk+A+mxvll/klL0RlfuIUei8BF7YWiua4kQqww==",
+      "license": "MIT",
+      "dependencies": {
+        "@tufjs/canonical-json": "2.0.0",
+        "minimatch": "^10.1.1"
       },
       "engines": {
         "node": "^20.17.0 || >=22.9.0"
       }
     },
+    "node_modules/tuf-js/node_modules/minimatch": {
+      "version": "10.1.1",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-10.1.1.tgz",
+      "integrity": "sha512-enIvLvRAFZYXJzkCYG5RKmPfrFArdLv+R+lbQ53BmIMLIry74bjKzX6iHAm8WYamJkhSSEabrWN5D97XnKObjQ==",
+      "license": "BlueOak-1.0.0",
+      "dependencies": {
+        "@isaacs/brace-expansion": "^5.0.0"
+      },
+      "engines": {
+        "node": "20 || >=22"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
     "node_modules/tunnel-agent": {
       "version": "0.6.0",
       "resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.6.0.tgz",
@@ -12831,7 +12863,6 @@
       "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
       "dev": true,
       "license": "Apache-2.0",
-      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -13499,7 +13530,7 @@
       "license": "Apache-2.0",
       "dependencies": {
         "@sigstore/protobuf-specs": "^0.5.0",
-        "tuf-js": "^4.0.0"
+        "tuf-js": "^4.1.0"
       },
       "devDependencies": {
         "@sigstore/jest": "^0.0.0",
diff --git a/packages/tuf/package.json b/packages/tuf/package.json
index 479dd1cb..f764cc3b 100644
--- a/packages/tuf/package.json
+++ b/packages/tuf/package.json
@@ -33,7 +33,7 @@
   },
   "dependencies": {
     "@sigstore/protobuf-specs": "^0.5.0",
-    "tuf-js": "^4.0.0"
+    "tuf-js": "^4.1.0"
   },
   "engines": {
     "node": "^20.17.0 || >=22.9.0"
diff --git a/packages/tuf/src/client.ts b/packages/tuf/src/client.ts
index bfa08caa..80f90f44 100644
--- a/packages/tuf/src/client.ts
+++ b/packages/tuf/src/client.ts
@@ -17,6 +17,7 @@ import fs from 'fs';
 import path from 'path';
 import { Config, Updater } from 'tuf-js';
 import { TUFError } from '.';
+import { name as packageName, version } from '../package.json';
 import { readTarget } from './target';
 
 import type { MakeFetchHappenOptions } from 'make-fetch-happen';
@@ -162,6 +163,7 @@ function initClient(
   const config: Partial<Config> = {
     fetchTimeout: options.timeout,
     fetchRetry: options.retry,
+    userAgent: `${encodeURIComponent(packageName)}/${version}`,
   };
 
   return new Updater({