diff --git a/filenames.gypi b/filenames.gypi
index 5f1fdc3b141f..af1942fc3697 100644
--- a/filenames.gypi
+++ b/filenames.gypi
@@ -63,6 +63,7 @@
       'lib/renderer/api/remote.js',
       'lib/renderer/api/screen.js',
       'lib/renderer/api/web-frame.js',
+      'lib/renderer/extensions/i18n.js',
     ],
     'js2c_sources': [
       'lib/common/asar.js',
diff --git a/lib/browser/chrome-extension.js b/lib/browser/chrome-extension.js
index fc49f5e06be5..97bf292f9e23 100644
--- a/lib/browser/chrome-extension.js
+++ b/lib/browser/chrome-extension.js
@@ -115,6 +115,10 @@ ipcMain.on('CHROME_RUNTIME_CONNECT', function (event, extensionId, connectInfo)
   page.webContents.sendToAll(`CHROME_RUNTIME_ONCONNECT_${extensionId}`, event.sender.id, portId, connectInfo)
 })
 
+ipcMain.on('CHROME_I18N_MANIFEST', function (event, extensionId) {
+  event.returnValue = manifestMap[extensionId]
+})
+
 ipcMain.on('CHROME_RUNTIME_SENDMESSAGE', function (event, extensionId, message) {
   const page = backgroundPages[extensionId]
   if (!page) {
diff --git a/lib/renderer/chrome-api.js b/lib/renderer/chrome-api.js
index 17c3f5bfbd1a..4a3556c37e67 100644
--- a/lib/renderer/chrome-api.js
+++ b/lib/renderer/chrome-api.js
@@ -199,4 +199,6 @@ exports.injectTo = function (extensionId, isBackgroundPage, context) {
     setPopup () {},
     getPopup () {}
   }
+
+  chrome.i18n = require('./extensions/i18n.js').setup(extensionId)
 }
diff --git a/lib/renderer/extensions/i18n.js b/lib/renderer/extensions/i18n.js
new file mode 100644
index 000000000000..d0279601f43d
--- /dev/null
+++ b/lib/renderer/extensions/i18n.js
@@ -0,0 +1,84 @@
+// Implementation of chrome.i18n.getMessage
+// https://developer.chrome.com/extensions/i18n#method-getMessage
+//
+// Does not implement predefined messages:
+// https://developer.chrome.com/extensions/i18n#overview-predefined
+
+const {ipcRenderer} = require('electron')
+const fs = require('fs')
+const path = require('path')
+
+let metadata
+
+const getExtensionMetadata = (extensionId) => {
+  if (!metadata) {
+    metadata = ipcRenderer.sendSync('CHROME_I18N_MANIFEST', extensionId)
+  }
+  return metadata
+}
+
+const getMessagesPath = (extensionId, language) => {
+  const metadata = getExtensionMetadata(extensionId)
+  const defaultLocale = metadata.default_locale || 'en'
+  const localesDirectory = path.join(metadata.srcDirectory, '_locales')
+  let messagesPath = path.join(localesDirectory, language, 'messages.json')
+  if (!fs.statSyncNoException(messagesPath)) {
+    messagesPath = path.join(localesDirectory, defaultLocale, 'messages.json')
+  }
+  return messagesPath
+}
+
+const getMessages = (extensionId, language) => {
+  try {
+    const messagesPath = getMessagesPath(extensionId, language)
+    return JSON.parse(fs.readFileSync(messagesPath)) || {}
+  } catch (error) {
+    return {}
+  }
+}
+
+const getLanguage = () => {
+  return navigator.language.replace(/-.*$/, '').toLowerCase()
+}
+
+const replaceNumberedSubstitutions = (message, substitutions) => {
+  return message.replace(/\$(\d+)/, (_, number) => {
+    const index = parseInt(number, 10) - 1
+    return substitutions[index] || ''
+  })
+}
+
+const replacePlaceholders = (message, placeholders, substitutions) => {
+  if (typeof substitutions === 'string') {
+    substitutions = [substitutions]
+  }
+  if (!Array.isArray(substitutions)) {
+    substitutions = []
+  }
+
+  if (placeholders) {
+    Object.keys(placeholders).forEach((name) => {
+      let {content} = placeholders[name]
+      content = replaceNumberedSubstitutions(content, substitutions)
+      message = message.replace(new RegExp(`\\$${name}\\$`, 'gi'), content)
+    })
+  }
+
+  return replaceNumberedSubstitutions(message, substitutions)
+}
+
+const getMessage = (extensionId, messageName, substitutions) => {
+  const messages = getMessages(extensionId, getLanguage())
+  if (messages.hasOwnProperty(messageName)) {
+    const {message, placeholders} = messages[messageName]
+    return replacePlaceholders(message, placeholders, substitutions)
+  }
+}
+
+exports.setup = (extensionId) => {
+  return {
+    getMessage (messageName, substitutions) {
+      return getMessage(extensionId, messageName, substitutions)
+    }
+  }
+}
diff --git a/spec/api-browser-window-spec.js b/spec/api-browser-window-spec.js
index bad3b80a9b5c..cf3442d59ce4 100644
--- a/spec/api-browser-window-spec.js
+++ b/spec/api-browser-window-spec.js
@@ -865,6 +865,7 @@ describe('browser-window module', function () {
           ipcMain.once('answer', function (event, message) {
             assert.equal(message.runtimeId, 'foo')
             assert.equal(message.tabId, w.webContents.id)
+            assert.equal(message.i18nString, 'foo - bar (baz)')
             done()
           })
         })
diff --git a/spec/fixtures/devtools-extensions/foo/_locales/en/messages.json b/spec/fixtures/devtools-extensions/foo/_locales/en/messages.json
new file mode 100644
index 000000000000..fe5653c2b411
--- /dev/null
+++ b/spec/fixtures/devtools-extensions/foo/_locales/en/messages.json
@@ -0,0 +1,10 @@
+{
+  "foo": {
+    "message": "foo - $BAZ$ ($2)",
+    "placeholders": {
+      "baz": {
+        "content": "$1"
+      }
+    }
+  }
+}
diff --git a/spec/fixtures/devtools-extensions/foo/index.html b/spec/fixtures/devtools-extensions/foo/index.html
index 2e0a29aff3d0..414370ae2c06 100644
--- a/spec/fixtures/devtools-extensions/foo/index.html
+++ b/spec/fixtures/devtools-extensions/foo/index.html
@@ -6,7 +6,8 @@
     <script>
       var message = JSON.stringify({
         runtimeId: chrome.runtime.id,
-        tabId: chrome.devtools.inspectedWindow.tabId
+        tabId: chrome.devtools.inspectedWindow.tabId,
+        i18nString: chrome.i18n.getMessage('foo', ['bar', 'baz'])
       })
       var sendMessage = `require('electron').ipcRenderer.send('answer', ${message})`
       window.chrome.devtools.inspectedWindow.eval(sendMessage, function () {})
diff --git a/spec/fixtures/devtools-extensions/foo/manifest.json b/spec/fixtures/devtools-extensions/foo/manifest.json
index 413853e8d351..b88ab65a1ea8 100644
--- a/spec/fixtures/devtools-extensions/foo/manifest.json
+++ b/spec/fixtures/devtools-extensions/foo/manifest.json
@@ -1,5 +1,6 @@
 {
   "name": "foo",
   "version": "1.0",
-  "devtools_page": "foo.html"
+  "devtools_page": "foo.html",
+  "default_locale": "en"
 }