--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1262,16 +1262,18 @@ var gBrowserInit = {
       }
       initBrowser.removeAttribute("blank");
     }
 
     gBrowser.updateBrowserRemoteness(initBrowser, isRemote, {
       remoteType, sameProcessAsFrameLoader
     });
 
+    BrowserSearch.initPlaceHolder();
+
     // Hack to ensure that the about:home favicon is loaded
     // instantaneously, to avoid flickering and improve perceived performance.
     this._callWithURIToLoad(uriToLoad => {
       if (uriToLoad == "about:home") {
         gBrowser.setIcon(gBrowser.selectedTab, "chrome://branding/content/icon32.png");
       } else if (uriToLoad == "about:privatebrowsing") {
         gBrowser.setIcon(gBrowser.selectedTab, "chrome://browser/skin/privatebrowsing/favicon.svg");
       }
@@ -1457,16 +1459,17 @@ var gBrowserInit = {
     // We do this before the session restore service gets initialized so we can
     // apply full zoom settings to tabs restored by the session restore service.
     FullZoom.init();
     PanelUI.init();
 
     UpdateUrlbarSearchSplitterState();
 
     BookmarkingUI.init();
+    BrowserSearch.delayedStartupInit();
     AutoShowBookmarksToolbar.init();
 
     Services.prefs.addObserver(gHomeButton.prefDomain, gHomeButton);
 
     var homeButton = document.getElementById("home-button");
     gHomeButton.updateTooltip(homeButton);
 
     let safeMode = document.getElementById("helpSafeMode");
@@ -3743,20 +3746,35 @@ const DOMEventHandler = {
     if (!tab)
       return;
 
     BrowserSearch.addEngine(aBrowser, aEngine, makeURI(aURL));
   },
 };
 
 const BrowserSearch = {
+  _searchInitComplete: false,
+
   init() {
     Services.obs.addObserver(this, "browser-search-engine-modified");
   },
 
+  delayedStartupInit() {
+    // Asynchronously initialize the search service if necessary, to get the
+    // current engine for working out the placeholder.
+    Services.search.init(rv => {
+      if (Components.isSuccessCode(rv)) {
+        // Delay the update for this until so that we don't change it while
+        // the user is looking at it / isn't expecting it.
+        this._updateURLBarPlaceholder(Services.search.currentEngine, true);
+        this._searchInitComplete = true;
+      }
+    });
+  },
+
   uninit() {
     Services.obs.removeObserver(this, "browser-search-engine-modified");
   },
 
   observe(engine, topic, data) {
     // There are two kinds of search engine objects, nsISearchEngine objects and
     // plain { uri, title, icon } objects.  `engine` in this method is the
     // former.  The browser.engines and browser.hiddenEngines arrays are the
@@ -3773,16 +3791,21 @@ const BrowserSearch = {
       this._addMaybeOfferedEngine(engineName);
       break;
     case "engine-added":
       // An engine was added to the search service.  If a page is offering the
       // engine, then the engine needs to be removed from the corresponding
       // browser's offered engines.
       this._removeMaybeOfferedEngine(engineName);
       break;
+    case "engine-current":
+      if (this._searchInitComplete) {
+        this._updateURLBarPlaceholder(engine);
+      }
+      break;
     }
   },
 
   _addMaybeOfferedEngine(engineName) {
     let selectedBrowserOffersEngine = false;
     for (let browser of gBrowser.browsers) {
       for (let i = 0; i < (browser.hiddenEngines || []).length; i++) {
         if (browser.hiddenEngines[i].title == engineName) {
@@ -3820,16 +3843,98 @@ const BrowserSearch = {
         }
       }
     }
     if (selectedBrowserOffersEngine) {
       this.updateOpenSearchBadge();
     }
   },
 
+  /**
+   * Initializes the urlbar placeholder to the pre-saved engine name. We do this
+   * via a preference, to avoid needing to synchronously init the search service.
+   *
+   * This should be called around the time of DOMContentLoaded, so that it is
+   * initialized quickly before the user sees anything.
+   *
+   * Note: If the preference doesn't exist, we don't do anything as the default
+   * placeholder is a string which doesn't have the engine name.
+   */
+  initPlaceHolder() {
+    let engineName = Services.prefs.getStringPref("browser.urlbar.placeholderName", "");
+    if (engineName) {
+      // We can do this directly, since we know we're at DOMContentLoaded.
+      this._setURLBarPlaceholder(engineName);
+    }
+  },
+
+  /**
+   * Updates the URLBar placeholder for the specified engine, delaying the
+   * update if required. This also saves the current engine name in preferences
+   * for the next restart.
+   *
+   * Note: The engine name will only be displayed for built-in engines, as we
+   * know they should have short names.
+   *
+   * @param {nsISearchEngine} engine The search engine to use for the update.
+   * @param {Boolean} delayUpdate    Set to true, to delay update until the
+   *                                 placeholder is not displayed.
+   */
+  _updateURLBarPlaceholder(engine, delayUpdate = false) {
+    if (!engine) {
+      throw new Error("Expected an engine to be specified");
+    }
+
+    let engineName = "";
+    if (Services.search.getDefaultEngines().includes(engine)) {
+      engineName = engine.name;
+      Services.prefs.setStringPref("browser.urlbar.placeholderName", engineName);
+    } else {
+      Services.prefs.clearUserPref("browser.urlbar.placeholderName");
+    }
+
+    // Only delay if requested, and we're not displaying text in the URL bar
+    // currently.
+    if (delayUpdate && !gURLBar.value) {
+      // Delays changing the URL Bar placeholder until the user is not going to be
+      // seeing it, e.g. when there is a value entered in the bar, or if there is
+      // a tab switch to a tab which has a url loaded.
+      let placeholderUpdateListener = () => {
+        if (gURLBar.value) {
+          this._setURLBarPlaceholder(engineName);
+          gURLBar.removeEventListener("input", placeholderUpdateListener);
+          gBrowser.tabContainer.removeEventListener("TabSelect", placeholderUpdateListener);
+        }
+      };
+
+      gURLBar.addEventListener("input", placeholderUpdateListener);
+      gBrowser.tabContainer.addEventListener("TabSelect", placeholderUpdateListener);
+    } else {
+      this._setURLBarPlaceholder(engineName);
+    }
+  },
+
+  /**
+   * Sets the URLBar placeholder to either something based on the engine name,
+   * or the default placeholder.
+   *
+   * @param {String} name The name of the engine to use, an empty string if to
+   *                      use the default placeholder.
+   */
+  _setURLBarPlaceholder(name) {
+    let placeholder;
+    if (name) {
+      placeholder = gBrowserBundle.formatStringFromName("urlbar.placeholder",
+        [name], 1);
+    } else {
+      placeholder = gURLBar.getAttribute("defaultPlaceholder");
+    }
+    gURLBar.setAttribute("placeholder", placeholder);
+  },
+
   addEngine(browser, engine, uri) {
     // Check to see whether we've already added an engine with this title
     if (browser.engines) {
       if (browser.engines.some(e => e.title == engine.title))
         return;
     }
 
     var hidden = false;

--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -772,16 +772,17 @@
                        cui-areatype="toolbar"
                        aboutHomeOverrideTooltip="&abouthome.pageTitle;"/>
         <toolbarspring cui-areatype="toolbar" class="chromeclass-toolbar-additional"/>
         <toolbaritem id="urlbar-container" flex="400" persist="width"
                      removable="false"
                      class="chromeclass-location" overflows="false">
             <textbox id="urlbar" flex="1"
                      placeholder="&urlbar.placeholder2;"
+                     defaultPlaceholder="&urlbar.placeholder2;"
                      focused="true"
                      type="autocomplete"
                      autocompletesearch="unifiedcomplete"
                      autocompletesearchparam="enable-actions"
                      autocompletepopup="PopupAutoCompleteRichResult"
                      completeselectedindex="true"
                      shrinkdelay="250"
                      tabscrolling="true"

--- a/browser/base/content/test/urlbar/browser.ini
+++ b/browser/base/content/test/urlbar/browser.ini
@@ -90,16 +90,20 @@ uses-unsafe-cpows = true
 [browser_urlbarOneOffs.js]
 support-files =
   searchSuggestionEngine.xml
   searchSuggestionEngine.sjs
 [browser_urlbarOneOffs_searchSuggestions.js]
 support-files =
   searchSuggestionEngine.xml
   searchSuggestionEngine.sjs
+[browser_urlbarPlaceholder.js]
+support-files =
+  searchSuggestionEngine.xml
+  searchSuggestionEngine.sjs
 [browser_urlbarPrivateBrowsingWindowChange.js]
 [browser_urlbarRaceWithTabs.js]
 [browser_urlbarRevert.js]
 [browser_urlbarSearchSingleWordNotification.js]
 [browser_urlbarSearchSuggestions.js]
 support-files =
   searchSuggestionEngine.xml
   searchSuggestionEngine.sjs

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/urlbar/browser_urlbarPlaceholder.js
@@ -0,0 +1,93 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * This test ensures the placeholder is set correctly for different search
+ * engines.
+ */
+
+"use strict";
+
+const TEST_ENGINE_BASENAME = "searchSuggestionEngine.xml";
+
+const originalEngine = Services.search.currentEngine;
+const expectedString = gBrowserBundle.formatStringFromName("urlbar.placeholder",
+  [originalEngine.name], 1);
+var extraEngine;
+var tabs = [];
+
+add_task(async function setup() {
+  extraEngine = await promiseNewSearchEngine(TEST_ENGINE_BASENAME);
+
+  // Force display of a tab with a URL bar, to clear out any possible placeholder
+  // initialization listeners that happen on startup.
+  let urlTab = await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:mozilla");
+  BrowserTestUtils.removeTab(urlTab);
+
+  registerCleanupFunction(() => {
+    Services.search.currentEngine = originalEngine;
+    for (let tab of tabs) {
+      BrowserTestUtils.removeTab(tab);
+    }
+  });
+});
+
+add_task(async function test_change_default_engine_updates_placeholder() {
+  tabs.push(await BrowserTestUtils.openNewForegroundTab(gBrowser));
+
+  Services.search.currentEngine = extraEngine;
+
+  await TestUtils.waitForCondition(
+    () => gURLBar.getAttribute("placeholder") == gURLBar.getAttribute("defaultPlaceholder"),
+    "The placeholder should match the default placeholder for non-built-in engines.");
+
+  Services.search.currentEngine = originalEngine;
+
+  await TestUtils.waitForCondition(
+    () => gURLBar.getAttribute("placeholder") == expectedString,
+    "The placeholder should include the engine name for built-in engines.");
+});
+
+add_task(async function test_delayed_update_placeholder() {
+  // Since we can't easily test for startup changes, we'll at least test the delay
+  // of update for the placeholder works.
+  let urlTab = await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:mozilla");
+  tabs.push(urlTab);
+
+  // Open a tab with a blank URL bar.
+  let blankTab = await BrowserTestUtils.openNewForegroundTab(gBrowser);
+  tabs.push(blankTab);
+
+  // Pretend we've "initialized".
+  BrowserSearch._updateURLBarPlaceholder(extraEngine, true);
+
+  Assert.equal(gURLBar.getAttribute("placeholder"), expectedString,
+    "Placeholder should be unchanged.");
+
+  // Now switch to a tab with something in the URL Bar.
+  await BrowserTestUtils.switchTab(gBrowser, urlTab);
+
+  await TestUtils.waitForCondition(
+    () => gURLBar.getAttribute("placeholder") == gURLBar.getAttribute("defaultPlaceholder"),
+    "The placeholder should have updated in the background.");
+
+  // Do it the other way to check both named engine and fallback code paths.
+  await BrowserTestUtils.switchTab(gBrowser, blankTab);
+
+  BrowserSearch._updateURLBarPlaceholder(originalEngine, true);
+
+  Assert.equal(gURLBar.getAttribute("placeholder"), gURLBar.getAttribute("defaultPlaceholder"),
+    "Placeholder should be unchanged.");
+
+  await BrowserTestUtils.switchTab(gBrowser, urlTab);
+
+  await TestUtils.waitForCondition(
+    () => gURLBar.getAttribute("placeholder") == expectedString,
+    "The placeholder should include the engine name for built-in engines.");
+
+  // Now check when we have a URL displayed, the placeholder is updated straight away.
+  BrowserSearch._updateURLBarPlaceholder(extraEngine);
+
+  Assert.equal(gURLBar.getAttribute("placeholder"), gURLBar.getAttribute("defaultPlaceholder"),
+    "Placeholder should be the default.");
+});

--- a/browser/locales/en-US/chrome/browser/browser.dtd
+++ b/browser/locales/en-US/chrome/browser/browser.dtd
@@ -429,17 +429,16 @@ These should match what Safari and other
 
 <!-- LOCALIZATION NOTE (moreMenu.label) This label is used in the new Photon
     app (hamburger) menu. When clicked, it opens a subview that contains
     secondary commands. -->
 <!ENTITY moreMenu.label "More">
 
 <!ENTITY openCmd.commandkey           "l">
 <!ENTITY urlbar.placeholder2          "Search or enter address">
-<!ENTITY urlbar.placeholder3          "Enter search terms and addresses here">
 <!ENTITY urlbar.accesskey             "d">
 <!-- LOCALIZATION NOTE (urlbar.extension.label): Used to indicate that a selected autocomplete entry is provided by an extension. -->
 <!ENTITY urlbar.extension.label       "Extension:">
 <!ENTITY urlbar.switchToTab.label     "Switch to tab:">
 
 <!-- LOCALIZATION NOTE (urlbar.searchSuggestionsNotification.hintPrefix): Shown just before the suggestions opt-out hint. -->
 <!ENTITY urlbar.searchSuggestionsNotification.hintPrefix "Tip:">
 <!-- LOCALIZATION NOTE (urlbar.searchSuggestionsNotification.hint): &#x1F50E; is the magnifier icon emoji, please don't change it. -->