diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 5bb5056b2..6ff8d244f 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -928,6 +928,9 @@
   "ok": {
     "message": "OK"
   },
+  "yes": {
+    "message": "Yes"
+  },
   "cancel": {
     "message": "Cancel"
   },
@@ -994,6 +997,9 @@
     "description":
       "Placeholder text in the message entry field when it is the first message sent to that contact"
   },
+  "sendMessageLeftGroup": {
+    "message": "You left this group"
+  },
   "groupMembers": {
     "message": "Group members"
   },
@@ -1917,6 +1923,17 @@
       "Button action that the user can click to rename the group or add a new member"
   },
 
+  "leaveGroup": {
+    "message": "Leave Group",
+    "description": "Button action that the user can click to leave the group"
+  },
+
+  "leaveGroupDialogTitle": {
+    "message": "Are you sure you want to leave this group?",
+    "description":
+      "Title shown to the user to confirm they want to leave the group"
+  },
+
   "copiedPublicKey": {
     "message": "Copied public key",
     "description": "A toast message telling the user that the key was copied"
diff --git a/js/background.js b/js/background.js
index ef707a912..4bb9ece96 100644
--- a/js/background.js
+++ b/js/background.js
@@ -763,6 +763,12 @@
       }
     });
 
+    Whisper.events.on('leaveGroup', async groupConvo => {
+      if (appView) {
+        appView.showLeaveGroupDialog(groupConvo);
+      }
+    });
+
     Whisper.events.on('deleteConversation', async conversation => {
       await conversation.destroyMessages();
       await window.Signal.Data.removeConversation(conversation.id, {
diff --git a/js/models/conversations.js b/js/models/conversations.js
index cf0eebcbd..b36b2ce77 100644
--- a/js/models/conversations.js
+++ b/js/models/conversations.js
@@ -671,6 +671,11 @@
         this.trigger('disable:input', true);
         return;
       }
+      if (!this.isPrivate() && this.get('left')) {
+        this.trigger('disable:input', true);
+        this.trigger('change:placeholder', 'left-group');
+        return;
+      }
       switch (this.get('friendRequestStatus')) {
         case FriendRequestStatusEnum.none:
         case FriendRequestStatusEnum.requestExpired:
@@ -1962,6 +1967,8 @@
             textsecure.messaging.leaveGroup(this.id, groupNumbers, options)
           )
         );
+
+        this.updateTextInputState();
       }
     },
 
diff --git a/js/models/messages.js b/js/models/messages.js
index de66e2200..b869fa88a 100644
--- a/js/models/messages.js
+++ b/js/models/messages.js
@@ -1816,6 +1816,8 @@
                 groupUpdate.joined = difference;
               }
               if (conversation.get('left')) {
+                // TODO: Maybe we shouldn't assume this message adds us:
+                // we could maybe still get this message by mistake
                 window.log.warn('re-added to a left group');
                 attributes.left = false;
               }
@@ -1885,6 +1887,9 @@
           attributes.active_at = now;
           conversation.set(attributes);
 
+          // Re-enable typing if re-joined the group
+          conversation.updateTextInputState();
+
           if (message.isExpirationTimerUpdate()) {
             message.set({
               expirationTimerUpdate: {
diff --git a/js/modules/signal.js b/js/modules/signal.js
index a33373f10..94162c9c9 100644
--- a/js/modules/signal.js
+++ b/js/modules/signal.js
@@ -50,6 +50,7 @@ const {
 const {
   UpdateGroupDialog,
 } = require('../../ts/components/conversation/UpdateGroupDialog');
+const { ConfirmDialog } = require('../../ts/components/ConfirmDialog');
 const {
   MediaGallery,
 } = require('../../ts/components/conversation/media-gallery/MediaGallery');
@@ -226,6 +227,7 @@ exports.setup = (options = {}) => {
     MainHeader,
     MemberList,
     CreateGroupDialog,
+    ConfirmDialog,
     UpdateGroupDialog,
     MediaGallery,
     Message,
diff --git a/js/views/app_view.js b/js/views/app_view.js
index f40e1af1f..81ddb94d7 100644
--- a/js/views/app_view.js
+++ b/js/views/app_view.js
@@ -215,5 +215,9 @@
       const dialog = new Whisper.UpdateGroupDialogView(groupConvo);
       this.el.append(dialog.el);
     },
+    showLeaveGroupDialog(groupConvo) {
+      const dialog = new Whisper.LeaveGroupDialogView(groupConvo);
+      this.el.append(dialog.el);
+    },
   });
 })();
diff --git a/js/views/conversation_view.js b/js/views/conversation_view.js
index cbe28b2ee..137016358 100644
--- a/js/views/conversation_view.js
+++ b/js/views/conversation_view.js
@@ -272,6 +272,10 @@
           onUpdateGroup: () => {
             window.Whisper.events.trigger('updateGroup', this.model);
           },
+
+          onLeaveGroup: () => {
+            window.Whisper.events.trigger('leaveGroup', this.model);
+          },
         };
       };
       this.titleView = new Whisper.ReactWrapperView({
@@ -440,6 +444,9 @@
         case 'disabled':
           placeholder = i18n('sendMessageDisabled');
           break;
+        case 'left-group':
+          placeholder = i18n('sendMessageLeftGroup');
+          break;
         default:
           placeholder = i18n('sendMessage');
           break;
diff --git a/js/views/create_group_dialog_view.js b/js/views/create_group_dialog_view.js
index f34d03844..28a89c757 100644
--- a/js/views/create_group_dialog_view.js
+++ b/js/views/create_group_dialog_view.js
@@ -46,8 +46,48 @@
     },
   });
 
+  Whisper.LeaveGroupDialogView = Whisper.View.extend({
+    className: 'loki-dialog modal',
+    initialize(groupConvo) {
+      this.groupConvo = groupConvo;
+      this.titleText = groupConvo.get('name');
+      this.messageText = i18n('leaveGroupDialogTitle');
+      this.okText = i18n('yes');
+      this.cancelText = i18n('cancel');
+
+      this.close = this.close.bind(this);
+      this.confirm = this.confirm.bind(this);
+
+      this.$el.focus();
+      this.render();
+    },
+    render() {
+      this.dialogView = new Whisper.ReactWrapperView({
+        className: 'leave-group-dialog',
+        Component: window.Signal.Components.ConfirmDialog,
+        props: {
+          titleText: this.titleText,
+          messageText: this.messageText,
+          okText: this.okText,
+          cancelText: this.cancelText,
+          onConfirm: this.confirm,
+          onClose: this.close,
+        },
+      });
+
+      this.$el.append(this.dialogView.el);
+      return this;
+    },
+    async confirm() {
+      await this.groupConvo.leaveGroup();
+      this.close();
+    },
+    close() {
+      this.remove();
+    },
+  });
+
   Whisper.UpdateGroupDialogView = Whisper.View.extend({
-    templateName: 'group-creation-template',
     className: 'loki-dialog modal',
     initialize(groupConvo) {
       this.groupName = groupConvo.get('name');
diff --git a/stylesheets/_mentions.scss b/stylesheets/_mentions.scss
index ceb0a91af..22e7d727f 100644
--- a/stylesheets/_mentions.scss
+++ b/stylesheets/_mentions.scss
@@ -1,3 +1,30 @@
+.leave-group-dialog {
+  .content {
+    max-width: 100% !important;
+  }
+
+  .titleText {
+    font-size: large;
+    text-align: center;
+    margin: 2px;
+  }
+
+  .ok {
+    background-color: orangered;
+    min-width: 70px;
+    border: none;
+
+    &:hover {
+      background-color: red;
+    }
+  }
+
+  .cancel {
+    border: none;
+    min-width: 70px;
+  }
+}
+
 .create-group-dialog {
   .content {
     max-width: 100% !important;
diff --git a/ts/components/ConfirmDialog.tsx b/ts/components/ConfirmDialog.tsx
new file mode 100644
index 000000000..0a1cb510e
--- /dev/null
+++ b/ts/components/ConfirmDialog.tsx
@@ -0,0 +1,33 @@
+import React from 'react';
+
+interface Props {
+  titleText: string;
+  messageText: string;
+  okText: string;
+  cancelText: string;
+  onConfirm: any;
+  onClose: any;
+}
+
+export class ConfirmDialog extends React.Component<Props> {
+  constructor(props: any) {
+    super(props);
+  }
+
+  public render() {
+    return (
+      <div className="content">
+        <p className="titleText">{this.props.titleText}</p>
+        <p className="messageText">{this.props.messageText}</p>
+        <div className="buttons">
+          <button className="cancel" tabIndex={0} onClick={this.props.onClose}>
+            {this.props.cancelText}
+          </button>
+          <button className="ok" tabIndex={0} onClick={this.props.onConfirm}>
+            {this.props.okText}
+          </button>
+        </div>
+      </div>
+    );
+  }
+}
diff --git a/ts/components/conversation/ConversationHeader.tsx b/ts/components/conversation/ConversationHeader.tsx
index f97c42ffe..4a7223b5c 100644
--- a/ts/components/conversation/ConversationHeader.tsx
+++ b/ts/components/conversation/ConversationHeader.tsx
@@ -63,6 +63,7 @@ interface Props {
   onCopyPublicKey: () => void;
 
   onUpdateGroup: () => void;
+  onLeaveGroup: () => void;
 
   i18n: LocalizerType;
 }
@@ -225,6 +226,7 @@ export class ConversationHeader extends React.Component<Props> {
       onDeleteContact,
       onCopyPublicKey,
       onUpdateGroup,
+      onLeaveGroup,
     } = this.props;
 
     return (
@@ -233,6 +235,7 @@ export class ConversationHeader extends React.Component<Props> {
         <MenuItem onClick={onCopyPublicKey}>{i18n('copyPublicKey')}</MenuItem>
         <MenuItem onClick={onDeleteMessages}>{i18n('deleteMessages')}</MenuItem>
         <MenuItem onClick={onUpdateGroup}>{i18n('updateGroup')}</MenuItem>
+        <MenuItem onClick={onLeaveGroup}>{i18n('leaveGroup')}</MenuItem>
         {!isMe && isClosable ? (
           !isPublic ? (
             <MenuItem onClick={onDeleteContact}>