diff --git a/app/javascript/flavours/glitch/actions/compose.js b/app/javascript/flavours/glitch/actions/compose.js
index f6c8086fe1a..b9248169f39 100644
--- a/app/javascript/flavours/glitch/actions/compose.js
+++ b/app/javascript/flavours/glitch/actions/compose.js
@@ -3,6 +3,7 @@ import { CancelToken } from 'axios';
 import { throttle } from 'lodash';
 import { search as emojiSearch } from 'flavours/glitch/util/emoji/emoji_mart_search_light';
 import { useEmoji } from './emojis';
+import { tagHistory } from 'flavours/glitch/util/settings';
 import resizeImage from 'flavours/glitch/util/resize_image';
 
 import { updateTimeline } from './timelines';
@@ -28,6 +29,9 @@ export const COMPOSE_UPLOAD_UNDO     = 'COMPOSE_UPLOAD_UNDO';
 export const COMPOSE_SUGGESTIONS_CLEAR = 'COMPOSE_SUGGESTIONS_CLEAR';
 export const COMPOSE_SUGGESTIONS_READY = 'COMPOSE_SUGGESTIONS_READY';
 export const COMPOSE_SUGGESTION_SELECT = 'COMPOSE_SUGGESTION_SELECT';
+export const COMPOSE_SUGGESTION_TAGS_UPDATE = 'COMPOSE_SUGGESTION_TAGS_UPDATE';
+
+export const COMPOSE_TAG_HISTORY_UPDATE = 'COMPOSE_TAG_HISTORY_UPDATE';
 
 export const COMPOSE_MOUNT   = 'COMPOSE_MOUNT';
 export const COMPOSE_UNMOUNT = 'COMPOSE_UNMOUNT';
@@ -136,6 +140,7 @@ export function submitCompose() {
         'Idempotency-Key': getState().getIn(['compose', 'idempotencyKey']),
       },
     }).then(function (response) {
+      dispatch(insertIntoTagHistory(response.data.tags));
       dispatch(submitComposeSuccess({ ...response.data }));
 
       //  If the response has no data then we can't do anything else.
@@ -315,12 +320,22 @@ const fetchComposeSuggestionsEmojis = (dispatch, getState, token) => {
   dispatch(readyComposeSuggestionsEmojis(token, results));
 };
 
+const fetchComposeSuggestionsTags = (dispatch, getState, token) => {
+  dispatch(updateSuggestionTags(token));
+};
+
 export function fetchComposeSuggestions(token) {
   return (dispatch, getState) => {
-    if (token[0] === ':') {
+    switch (token[0]) {
+    case ':':
       fetchComposeSuggestionsEmojis(dispatch, getState, token);
-    } else {
+      break;
+    case '#':
+      fetchComposeSuggestionsTags(dispatch, getState, token);
+      break;
+    default:
       fetchComposeSuggestionsAccounts(dispatch, getState, token);
+      break;
     }
   };
 };
@@ -343,10 +358,15 @@ export function readyComposeSuggestionsAccounts(token, accounts) {
 
 export function selectComposeSuggestion(position, token, suggestion) {
   return (dispatch, getState) => {
-    const completion = typeof suggestion === 'object' && suggestion.id ? (
-      dispatch(useEmoji(suggestion)),
-      suggestion.native || suggestion.colons
-    ) : '@' + getState().getIn(['accounts', suggestion, 'acct']);
+    let completion;
+    if (typeof suggestion === 'object' && suggestion.id) {
+      dispatch(useEmoji(suggestion));
+      completion = suggestion.native || suggestion.colons;
+    } else if (suggestion[0] === '#') {
+      completion = suggestion;
+    } else {
+      completion = '@' + getState().getIn(['accounts', suggestion, 'acct']);
+    }
 
     dispatch({
       type: COMPOSE_SUGGESTION_SELECT,
@@ -357,6 +377,48 @@ export function selectComposeSuggestion(position, token, suggestion) {
   };
 };
 
+export function updateSuggestionTags(token) {
+  return {
+    type: COMPOSE_SUGGESTION_TAGS_UPDATE,
+    token,
+  };
+}
+
+export function updateTagHistory(tags) {
+  return {
+    type: COMPOSE_TAG_HISTORY_UPDATE,
+    tags,
+  };
+}
+
+export function hydrateCompose() {
+  return (dispatch, getState) => {
+    const me = getState().getIn(['meta', 'me']);
+    const history = tagHistory.get(me);
+
+    if (history !== null) {
+      dispatch(updateTagHistory(history));
+    }
+  };
+}
+
+function insertIntoTagHistory(tags) {
+  return (dispatch, getState) => {
+    const state = getState();
+    const oldHistory = state.getIn(['compose', 'tagHistory']);
+    const me = state.getIn(['meta', 'me']);
+    const names = tags.map(({ name }) => name);
+    const intersectedOldHistory = oldHistory.filter(name => !names.includes(name));
+
+    names.push(...intersectedOldHistory.toJS());
+
+    const newHistory = names.slice(0, 1000);
+
+    tagHistory.set(me, newHistory);
+    dispatch(updateTagHistory(newHistory));
+  };
+}
+
 export function mountCompose() {
   return {
     type: COMPOSE_MOUNT,
diff --git a/app/javascript/flavours/glitch/actions/store.js b/app/javascript/flavours/glitch/actions/store.js
index a1db0fdd51c..2dd94a99832 100644
--- a/app/javascript/flavours/glitch/actions/store.js
+++ b/app/javascript/flavours/glitch/actions/store.js
@@ -1,4 +1,5 @@
 import { Iterable, fromJS } from 'immutable';
+import { hydrateCompose } from './compose';
 
 export const STORE_HYDRATE = 'STORE_HYDRATE';
 export const STORE_HYDRATE_LAZY = 'STORE_HYDRATE_LAZY';
@@ -8,10 +9,14 @@ const convertState = rawState =>
     Iterable.isIndexed(v) ? v.toList() : v.toMap());
 
 export function hydrateStore(rawState) {
-  const state = convertState(rawState);
+  return dispatch => {
+    const state = convertState(rawState);
 
-  return {
-    type: STORE_HYDRATE,
-    state,
+    dispatch({
+      type: STORE_HYDRATE,
+      state,
+    });
+
+    dispatch(hydrateCompose());
   };
 };
diff --git a/app/javascript/flavours/glitch/features/composer/textarea/index.js b/app/javascript/flavours/glitch/features/composer/textarea/index.js
index 51d44a83be7..50e46fc784c 100644
--- a/app/javascript/flavours/glitch/features/composer/textarea/index.js
+++ b/app/javascript/flavours/glitch/features/composer/textarea/index.js
@@ -58,7 +58,7 @@ const handlers = {
     const right = value.slice(selectionStart).search(/[\s\u200B]/);
     const token = function () {
       switch (true) {
-      case left < 0 || !/[@:]/.test(value[left]):
+      case left < 0 || !/[@:#]/.test(value[left]):
         return null;
       case right < 0:
         return value.slice(left);
diff --git a/app/javascript/flavours/glitch/features/composer/textarea/suggestions/item/index.js b/app/javascript/flavours/glitch/features/composer/textarea/suggestions/item/index.js
index f55640bcf93..33169239862 100644
--- a/app/javascript/flavours/glitch/features/composer/textarea/suggestions/item/index.js
+++ b/app/javascript/flavours/glitch/features/composer/textarea/suggestions/item/index.js
@@ -57,6 +57,42 @@ export default class ComposerTextareaSuggestionsItem extends React.Component {
     } = this.props;
     const computedClass = classNames('composer--textarea--suggestions--item', { selected });
 
+    //  If the suggestion is an object, then we render an emoji.
+    //  Otherwise, we render a hashtag if it starts with #, or an account.
+    let inner;
+    if (typeof suggestion === 'object') {
+      let url;
+      if (suggestion.custom) {
+        url = suggestion.imageUrl;
+      } else {
+        const mapping = unicodeMapping[suggestion.native] || unicodeMapping[suggestion.native.replace(/\uFE0F$/, '')];
+        if (mapping) {
+          url = `${assetHost}/emoji/${mapping.filename}.svg`;
+        }
+      }
+      if (url) {
+        inner = (
+          <div className='emoji'>
+            <img
+              alt={suggestion.native || suggestion.colons}
+              className='emojione'
+              src={url}
+            />
+            {suggestion.colons}
+          </div>
+        );
+      }
+    } else if (suggestion[0] === '#') {
+      inner = suggestion;
+    } else {
+      inner = (
+        <AccountContainer
+          id={suggestion}
+          small
+        />
+      );
+    }
+
     //  The result.
     return (
       <div
@@ -66,37 +102,7 @@ export default class ComposerTextareaSuggestionsItem extends React.Component {
         role='button'
         tabIndex='0'
       >
-        { //  If the suggestion is an object, then we render an emoji.
-          //  Otherwise, we render an account.
-          typeof suggestion === 'object' ? function () {
-            const url = function () {
-              if (suggestion.custom) {
-                return suggestion.imageUrl;
-              } else {
-                const mapping = unicodeMapping[suggestion.native] || unicodeMapping[suggestion.native.replace(/\uFE0F$/, '')];
-                if (!mapping) {
-                  return null;
-                }
-                return `${assetHost}/emoji/${mapping.filename}.svg`;
-              }
-            }();
-            return url ? (
-              <div className='emoji'>
-                <img
-                  alt={suggestion.native || suggestion.colons}
-                  className='emojione'
-                  src={url}
-                />
-                {suggestion.colons}
-              </div>
-            ) : null;
-          }() : (
-            <AccountContainer
-              id={suggestion}
-              small
-            />
-          )
-        }
+        { inner }
       </div>
     );
   }
diff --git a/app/javascript/flavours/glitch/reducers/compose.js b/app/javascript/flavours/glitch/reducers/compose.js
index 5ef5d3f5c58..9c4f1102375 100644
--- a/app/javascript/flavours/glitch/reducers/compose.js
+++ b/app/javascript/flavours/glitch/reducers/compose.js
@@ -18,6 +18,8 @@ import {
   COMPOSE_SUGGESTIONS_CLEAR,
   COMPOSE_SUGGESTIONS_READY,
   COMPOSE_SUGGESTION_SELECT,
+  COMPOSE_SUGGESTION_TAGS_UPDATE,
+  COMPOSE_TAG_HISTORY_UPDATE,
   COMPOSE_ADVANCED_OPTIONS_CHANGE,
   COMPOSE_SENSITIVITY_CHANGE,
   COMPOSE_SPOILERNESS_CHANGE,
@@ -77,6 +79,7 @@ const initialState = ImmutableMap({
   default_sensitive: false,
   resetFileKey: Math.floor((Math.random() * 0x10000)),
   idempotencyKey: null,
+  tagHistory: ImmutableList(),
   doodle: ImmutableMap({
     fg: 'rgb(  0,    0,    0)',
     bg: 'rgb(255,  255,  255)',
@@ -206,6 +209,18 @@ const insertSuggestion = (state, position, token, completion) => {
   });
 };
 
+const updateSuggestionTags = (state, token) => {
+  const prefix = token.slice(1);
+
+  return state.merge({
+    suggestions: state.get('tagHistory')
+      .filter(tag => tag.startsWith(prefix))
+      .slice(0, 4)
+      .map(tag => '#' + tag),
+    suggestion_token: token,
+  });
+};
+
 const insertEmoji = (state, position, emojiData) => {
   const emoji = emojiData.native;
 
@@ -360,6 +375,10 @@ export default function compose(state = initialState, action) {
     return state.set('suggestions', ImmutableList(action.accounts ? action.accounts.map(item => item.id) : action.emojis)).set('suggestion_token', action.token);
   case COMPOSE_SUGGESTION_SELECT:
     return insertSuggestion(state, action.position, action.token, action.completion);
+  case COMPOSE_SUGGESTION_TAGS_UPDATE:
+    return updateSuggestionTags(state, action.token);
+  case COMPOSE_TAG_HISTORY_UPDATE:
+    return state.set('tagHistory', fromJS(action.tags));
   case TIMELINE_DELETE:
     if (action.id === state.get('in_reply_to')) {
       return state.set('in_reply_to', null);
diff --git a/app/javascript/flavours/glitch/util/settings.js b/app/javascript/flavours/glitch/util/settings.js
index dbd969cb1bc..7643a508ea0 100644
--- a/app/javascript/flavours/glitch/util/settings.js
+++ b/app/javascript/flavours/glitch/util/settings.js
@@ -44,3 +44,4 @@ export default class Settings {
 }
 
 export const pushNotificationsSetting = new Settings('mastodon_push_notification_data');
+export const tagHistory = new Settings('mastodon_tag_history');