diff --git a/toolkit/mozapps/extensions/content/extensions.css b/toolkit/mozapps/extensions/content/extensions.css
index 41c1405657..3eeb173bde 100644
--- a/toolkit/mozapps/extensions/content/extensions.css
+++ b/toolkit/mozapps/extensions/content/extensions.css
@@ -202,10 +202,6 @@ setting[type="menulist"] {
   display: none;
 }
 
-#addons-page .view-pane:not([type="experiment"]) .experiment-info-container {
-  display: none;
-}
-
 .addon .relnotes {
   -moz-user-select: text;
 }
@@ -236,36 +232,6 @@ richlistitem:not([selected]) * {
   display: none;
 }
 
-#experiments-learn-more[disabled="true"] {
-  display: none;
-}
-
-#experiments-change-telemetry[disabled="true"] {
-  display: none;
-}
-
-.view-pane[type="experiment"] .error,
-.view-pane[type="experiment"] .warning,
-.view-pane[type="experiment"] .addon:not([pending="uninstall"]) .pending,
-.view-pane[type="experiment"] .disabled-postfix,
-.view-pane[type="experiment"] .update-postfix,
-.view-pane[type="experiment"] .version,
-#detail-view[type="experiment"] .alert-container,
-#detail-view[type="experiment"] #detail-version,
-#detail-view[type="experiment"] #detail-creator {
-  display: none;
-}
-
-.view-pane:not([type="experiment"]) .experiment-container,
-.view-pane:not([type="experiment"]) #detail-experiment-container {
-  display: none;
-}
-
-.addon[type="experiment"][status="installing"] .experiment-time,
-.addon[type="experiment"][status="installing"] .experiment-state {
-  display: none;
-}
-
 /* Indicator style for extension target application */
 .addon[native] .nativeIndicator {
   margin-left: 5pt;
diff --git a/toolkit/mozapps/extensions/content/extensions.xml b/toolkit/mozapps/extensions/content/extensions.xml
index 28feb19698..5eff5ff1eb 100644
--- a/toolkit/mozapps/extensions/content/extensions.xml
+++ b/toolkit/mozapps/extensions/content/extensions.xml
@@ -868,15 +868,6 @@
             <xul:label anonid="date-updated" class="date-updated"
                        unknown="&addon.unknownDate;"/>
           </xul:hbox>
-          <xul:hbox class="experiment-container">
-            <svg width="6" height="6" viewBox="0 0 6 6" version="1.1"
-                 xmlns="http://www.w3.org/2000/svg"
-                 class="experiment-bullet-container">
-              <circle cx="3" cy="3" r="3" class="experiment-bullet"/>
-            </svg>
-            <xul:label anonid="experiment-state" class="experiment-state"/>
-            <xul:label anonid="experiment-time" class="experiment-time"/>
-          </xul:hbox>
 
           <xul:hbox class="advancedinfo-container" flex="1">
             <xul:vbox class="description-outer-container" flex="1">
@@ -1042,12 +1033,6 @@
       <field name="_version">
         document.getAnonymousElementByAttribute(this, "anonid", "version");
       </field>
-      <field name="_experimentState">
-        document.getAnonymousElementByAttribute(this, "anonid", "experiment-state");
-      </field>
-      <field name="_experimentTime">
-        document.getAnonymousElementByAttribute(this, "anonid", "experiment-time");
-      </field>
       <field name="_icon">
         document.getAnonymousElementByAttribute(this, "anonid", "icon");
       </field>
@@ -1419,37 +1404,6 @@
           var showProgress = this.mAddon.purchaseURL || (this.mAddon.install &&
                              this.mAddon.install.state != AddonManager.STATE_INSTALLED);
           this._showStatus(showProgress ? "progress" : "none");
-
-          if (this.mAddon.type == "experiment") {
-            this.removeAttribute("notification");
-            let prefix = "experiment.";
-            let active = this.mAddon.isActive;
-
-            if (!showProgress) {
-              let stateKey = prefix + "state." + (active ? "active" : "complete");
-              this._experimentState.value = gStrings.ext.GetStringFromName(stateKey);
-
-              let now = Date.now();
-              let end = this.endDate;
-              let days = Math.abs(end - now) / (24 * 60 * 60 * 1000);
-
-              let timeKey = prefix + "time.";
-              let timeMessage;
-
-              if (days < 1) {
-                timeKey += (active ? "endsToday" : "endedToday");
-                timeMessage = gStrings.ext.GetStringFromName(timeKey);
-              } else {
-                timeKey += (active ? "daysRemaining" : "daysPassed");
-                days = Math.round(days);
-                let timeString = gStrings.ext.GetStringFromName(timeKey);
-                timeMessage = PluralForm.get(days, timeString)
-                                        .replace("#1", days);
-              }
-
-              this._experimentTime.value = timeMessage;
-            }
-          }
         ]]></body>
       </method>
 
diff --git a/toolkit/mozapps/extensions/content/extensions.xul b/toolkit/mozapps/extensions/content/extensions.xul
index 70ce55fa26..a61bb61627 100644
--- a/toolkit/mozapps/extensions/content/extensions.xul
+++ b/toolkit/mozapps/extensions/content/extensions.xul
@@ -91,8 +91,6 @@
     <command id="cmd_enableUpdateSecurity"/>
     <command id="cmd_toggleAutoUpdateDefault"/>
     <command id="cmd_resetAddonAutoUpdate"/>
-    <command id="cmd_experimentsLearnMore"/>
-    <command id="cmd_experimentsOpenTelemetryPreferences"/>
   </commandset>
 
   <!-- view commands - these act on the selected addon -->
@@ -354,22 +352,6 @@
               <spacer flex="5000"/> <!-- Necessary to allow the message to wrap -->
             </hbox>
           </hbox>
-          <hbox class="view-header global-info-container experiment-info-container">
-            <hbox class="global-info" flex="1" align="center">
-              <label value="&experiment.info.label;"/>
-              <button id="experiments-learn-more"
-                      label="&experiment.info.learnmore;"
-                      tooltiptext="&experiment.info.learnmore;"
-                      accesskey="&experiment.info.learnmore.accesskey;"
-                      command="cmd_experimentsLearnMore"/>
-              <button id="experiments-change-telemetry"
-                      label="&experiment.info.changetelemetry;"
-                      tooltiptext="&experiment.info.changetelemetry;"
-                      accesskey="&experiment.info.changetelemetry.accesskey;"
-                      command="cmd_experimentsOpenTelemetryPreferences"/>
-              <spacer flex="5000"/> <!-- Necessary to allow the message to wrap. -->
-            </hbox>
-          </hbox>
           <vbox id="addon-list-empty" class="alert-container"
                 flex="1" hidden="true">
             <spacer class="alert-spacer-before"/>
@@ -530,15 +512,6 @@
                     <label id="detail-creator" class="creator"/>
                     <label id="detail-translators" class="translators"/>
                   </vbox>
-                  <hbox id="detail-experiment-container">
-                    <svg width="8" height="8" viewBox="0 0 8 8" version="1.1"
-                         xmlns="http://www.w3.org/2000/svg"
-                         id="detail-experiment-bullet-container">
-                      <circle cx="4" cy="4" r="4" id="detail-experiment-bullet"/>
-                    </svg>
-                    <label id="detail-experiment-state"/>
-                    <label id="detail-experiment-time"/>
-                  </hbox>
                   <hbox id="detail-desc-container" align="start">
                     <vbox pack="center"> <!-- Necessary to work around bug 394738 -->
                       <image id="detail-screenshot" hidden="true"/>
diff --git a/toolkit/mozapps/extensions/internal/XPIProvider.jsm b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
index fb41087e18..f3125011e3 100644
--- a/toolkit/mozapps/extensions/internal/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
@@ -197,12 +197,10 @@ const TYPES = {
   locale: 8,
   multipackage: 32,
   dictionary: 64,
-  experiment: 128,
 };
 
 const RESTARTLESS_TYPES = new Set([
   "dictionary",
-  "experiment",
   "locale",
 ]);
 
@@ -944,30 +942,13 @@ function loadManifestFromRDF(aUri, aStream) {
   if (addon.type == "theme") {
     addon.userDisabled = !!LightweightThemeManager.currentTheme ||
                          addon.internalName != XPIProvider.selectedSkin;
-  }
-  // Experiments are disabled by default. It is up to the Experiments Manager
-  // to enable them (it drives installation).
-  else if (addon.type == "experiment") {
-    addon.userDisabled = true;
-  }
-  else {
+  } else {
     addon.userDisabled = false;
     addon.softDisabled = addon.blocklistState == Blocklist.STATE_SOFTBLOCKED;
   }
 
   addon.applyBackgroundUpdates = AddonManager.AUTOUPDATE_DEFAULT;
 
-  // Experiments are managed and updated through an external "experiments
-  // manager." So disable some built-in mechanisms.
-  if (addon.type == "experiment") {
-    addon.applyBackgroundUpdates = AddonManager.AUTOUPDATE_DISABLE;
-    addon.updateURL = null;
-    addon.updateKey = null;
-
-    addon.targetApplications = [];
-    addon.targetPlatforms = [];
-  }
-
   // Load the storage service before NSS (nsIRandomGenerator),
   // to avoid a SQLite initialization error (bug 717904).
   let storage = Services.storage;
@@ -1828,8 +1809,6 @@ this.XPIProvider = {
   // Keep track of the newest file in each add-on, in case we want to
   // report it.
   _mostRecentlyModifiedFile: {},
-  // Experiments are disabled by default. Track ones that are locally enabled.
-  _enabledExperiments: null,
   // A Map from an add-on install to its ID
   _addonFileMap: new Map(),
 #ifdef MOZ_DEVTOOLS
@@ -2003,8 +1982,6 @@ this.XPIProvider = {
       this.installLocationsByName = {};
       // Hook for tests to detect when saving database at shutdown time fails
       this._shutdownError = null;
-      // Clear the set of enabled experiments (experiments disabled by default).
-      this._enabledExperiments = new Set();
 
       let hasRegistry = ("nsIWindowsRegKey" in Ci);
 
@@ -2317,19 +2294,8 @@ this.XPIProvider = {
    * Persists changes to XPIProvider.bootstrappedAddons to its store (a pref).
    */
   persistBootstrappedAddons: function XPI_persistBootstrappedAddons() {
-    // Experiments are disabled upon app load, so don't persist references.
-    let filtered = {};
-    for (let id in this.bootstrappedAddons) {
-      let entry = this.bootstrappedAddons[id];
-      if (entry.type == "experiment") {
-        continue;
-      }
-
-      filtered[id] = entry;
-    }
-
     Services.prefs.setCharPref(PREF_BOOTSTRAP_ADDONS,
-                               JSON.stringify(filtered));
+                               JSON.stringify(this.bootstrappedAddons));
   },
 
   /**
@@ -4487,15 +4453,11 @@ this.XPIProvider = {
     let appDisabledChanged = aAddon.appDisabled != appDisabled;
 
     // Update the properties in the database.
-    // We never persist this for experiments because the disabled flags
-    // are controlled by the Experiments Manager.
-    if (aAddon.type != "experiment") {
-      XPIDatabase.setAddonProperties(aAddon, {
-        userDisabled: aUserDisabled,
-        appDisabled: appDisabled,
-        softDisabled: aSoftDisabled
-      });
-    }
+    XPIDatabase.setAddonProperties(aAddon, {
+      userDisabled: aUserDisabled,
+      appDisabled: appDisabled,
+      softDisabled: aSoftDisabled
+    });
 
     if (appDisabledChanged) {
       AddonManagerPrivate.callAddonListeners("onPropertyChanged",
@@ -6389,17 +6351,6 @@ AddonInternal.prototype = {
   },
 
   isCompatibleWith: function AddonInternal_isCompatibleWith(aAppVersion, aPlatformVersion) {
-    // Experiments are installed through an external mechanism that
-    // limits target audience to compatible clients. We trust it knows what
-    // it's doing and skip compatibility checks.
-    //
-    // This decision does forfeit defense in depth. If the experiments system
-    // is ever wrong about targeting an add-on to a specific application
-    // or platform, the client will likely see errors.
-    if (this.type == "experiment") {
-      return true;
-    }
-
     let app = this.matchingTargetApplication;
     if (!app)
       return false;
@@ -6610,13 +6561,6 @@ AddonInternal.prototype = {
     if (!(this.inDatabase))
       return permissions;
 
-    // Experiments can only be uninstalled. An uninstall reflects the user
-    // intent of "disable this experiment." This is partially managed by the
-    // experiments manager.
-    if (this.type == "experiment") {
-      return AddonManager.PERM_CAN_UNINSTALL;
-    }
-
     if (!this.appDisabled) {
       if (this.userDisabled || this.softDisabled) {
         permissions |= AddonManager.PERM_CAN_ENABLE;
@@ -6879,11 +6823,6 @@ function AddonWrapper(aAddon) {
     return aAddon.applyBackgroundUpdates;
   });
   this.__defineSetter__("applyBackgroundUpdates", function AddonWrapper_applyBackgroundUpdatesSetter(val) {
-    if (this.type == "experiment") {
-      logger.warn("Setting applyBackgroundUpdates on an experiment is not supported.");
-      return;
-    }
-
     if (val != AddonManager.AUTOUPDATE_DEFAULT &&
         val != AddonManager.AUTOUPDATE_DISABLE &&
         val != AddonManager.AUTOUPDATE_ENABLE) {
@@ -6948,15 +6887,10 @@ function AddonWrapper(aAddon) {
       return AddonManager.PENDING_UNINSTALL;
     }
 
-    // Extensions have an intentional inconsistency between what the DB says is
-    // enabled and what we say to the ouside world. so we need to cover up that
-    // lie here as well.
-    if (aAddon.type != "experiment") {
-      if (aAddon.active && aAddon.disabled)
-        pending |= AddonManager.PENDING_DISABLE;
-      else if (!aAddon.active && !aAddon.disabled)
-        pending |= AddonManager.PENDING_ENABLE;
-    }
+    if (aAddon.active && aAddon.disabled)
+      pending |= AddonManager.PENDING_DISABLE;
+    else if (!aAddon.active && !aAddon.disabled)
+      pending |= AddonManager.PENDING_ENABLE;
 
     if (aAddon.pendingUpgrade)
       pending |= AddonManager.PENDING_UPGRADE;
@@ -6993,10 +6927,6 @@ function AddonWrapper(aAddon) {
   });
 
   this.__defineGetter__("userDisabled", function AddonWrapper_userDisabledGetter() {
-    if (XPIProvider._enabledExperiments.has(aAddon.id)) {
-      return false;
-    }
-
     return aAddon.softDisabled || aAddon.userDisabled;
   });
   this.__defineSetter__("userDisabled", function AddonWrapper_userDisabledSetter(val) {
@@ -7004,14 +6934,6 @@ function AddonWrapper(aAddon) {
       return val;
     }
 
-    if (aAddon.type == "experiment") {
-      if (val) {
-        XPIProvider._enabledExperiments.delete(aAddon.id);
-      } else {
-        XPIProvider._enabledExperiments.add(aAddon.id);
-      }
-    }
-
     if (aAddon.inDatabase) {
       if (aAddon.type == "theme" && val) {
         if (aAddon.internalName == XPIProvider.defaultSkin)
@@ -7069,14 +6991,6 @@ function AddonWrapper(aAddon) {
   };
 
   this.findUpdates = function AddonWrapper_findUpdates(aListener, aReason, aAppVersion, aPlatformVersion) {
-    // Short-circuit updates for experiments because updates are handled
-    // through the Experiments Manager.
-    if (this.type == "experiment") {
-      AddonManagerPrivate.callNoUpdateListeners(this, aListener, aReason,
-                                                aAppVersion, aPlatformVersion);
-      return;
-    }
-
     new UpdateChecker(aAddon, aListener, aReason, aAppVersion, aPlatformVersion);
   };
 
@@ -7813,17 +7727,4 @@ var addonTypes = [
                                     AddonManager.TYPE_UI_HIDE_EMPTY | AddonManager.TYPE_SUPPORTS_UNDO_RESTARTLESS_UNINSTALL),
 ];
 
-// We only register experiments support if the application supports them.
-// Ideally, we would install an observer to watch the pref. Installing
-// an observer for this pref is not necessary here and may be buggy with
-// regards to registering this XPIProvider twice.
-if (Preferences.get("experiments.supported", false)) {
-  addonTypes.push(
-    new AddonManagerPrivate.AddonType("experiment",
-                                      URI_EXTENSION_STRINGS,
-                                      STRING_TYPE_NAME,
-                                      AddonManager.VIEW_TYPE_LIST, 11000,
-                                      AddonManager.TYPE_UI_HIDE_EMPTY | AddonManager.TYPE_SUPPORTS_UNDO_RESTARTLESS_UNINSTALL));
-}
-
 AddonManagerPrivate.registerProvider(XPIProvider, addonTypes);