diff --git a/app/assets/javascripts/application.js b/app/assets/javascripts/application.js
index 02bc257b12b..c6ca0b0c90c 100644
--- a/app/assets/javascripts/application.js
+++ b/app/assets/javascripts/application.js
@@ -25,6 +25,7 @@
 //= require ./discourse/lib/key-value-store
 //= require ./discourse/lib/computed
 //= require ./discourse/lib/formatter
+//= require ./discourse/lib/text-direction
 //= require ./discourse/lib/eyeline
 //= require ./discourse/lib/show-modal
 //= require ./discourse/mixins/scrolling
diff --git a/app/assets/javascripts/discourse/components/d-editor.js.es6 b/app/assets/javascripts/discourse/components/d-editor.js.es6
index c70f0b3bc96..10d1a4fa534 100644
--- a/app/assets/javascripts/discourse/components/d-editor.js.es6
+++ b/app/assets/javascripts/discourse/components/d-editor.js.es6
@@ -8,6 +8,7 @@ import { emojiSearch, isSkinTonableEmoji } from 'pretty-text/emoji';
 import { emojiUrlFor } from 'discourse/lib/text';
 import { getRegister } from 'discourse-common/lib/get-owner';
 import { findRawTemplate } from 'discourse/lib/raw-templates';
+import { siteDir } from 'discourse/lib/text-direction';
 import { determinePostReplaceSelection, clipboardData } from 'discourse/lib/utilities';
 import toMarkdown from 'discourse/lib/to-markdown';
 import deprecated from 'discourse-common/lib/deprecated';
@@ -107,6 +108,17 @@ class Toolbar {
       perform: e => e.applyList(i => !i ? "1. " : `${parseInt(i) + 1}. `, 'list_item')
     });
 
+    if (Discourse.SiteSettings.support_mixed_text_direction) {
+      this.addButton({
+        id: 'toggle-direction',
+        group: 'extras',
+        icon: 'arrows-h',
+        shortcut: 'Shift+6',
+        title: 'composer.toggle_direction',
+        perform: e => e.toggleDirection(),
+      });
+    }
+
     if (site.mobileView) {
       this.groups.push({group: 'mobileExtras', buttons: []});
     }
@@ -647,6 +659,14 @@ export default Ember.Component.extend({
     return null;
   },
 
+  _toggleDirection() {
+    const $textArea = $(".d-editor-input");
+    let currentDir = $textArea.attr('dir') ? $textArea.attr('dir') : siteDir(),
+        newDir = currentDir === 'ltr' ? 'rtl' : 'ltr';
+
+    $textArea.attr('dir', newDir).focus();
+  },
+
   paste(e) {
     if (!$(".d-editor-input").is(":focus")) {
       return;
@@ -724,6 +744,7 @@ export default Ember.Component.extend({
         addText: text => this._addText(selected, text),
         replaceText: text => this._addText({pre: '', post: ''}, text),
         getText: () => this.get('value'),
+        toggleDirection: () => this._toggleDirection(),
       };
 
       if (button.sendAction) {
diff --git a/app/assets/javascripts/discourse/components/text-field.js.es6 b/app/assets/javascripts/discourse/components/text-field.js.es6
index a9246efa7db..c2bb0eaf51c 100644
--- a/app/assets/javascripts/discourse/components/text-field.js.es6
+++ b/app/assets/javascripts/discourse/components/text-field.js.es6
@@ -1,7 +1,35 @@
 import computed from "ember-addons/ember-computed-decorators";
+import { siteDir } from "discourse/lib/text-direction";
+import { isRTL } from "discourse/lib/text-direction";
+import { isLTR } from "discourse/lib/text-direction";
 
 export default Ember.TextField.extend({
-  attributeBindings: ['autocorrect', 'autocapitalize', 'autofocus', 'maxLength'],
+  attributeBindings: ['autocorrect', 'autocapitalize', 'autofocus', 'maxLength', 'dir'],
+
+  @computed
+  dir() {
+    if (Discourse.SiteSettings.support_mixed_text_direction) {
+      let val = this.value;
+      if (val) {
+        return isRTL(val) ? 'rtl' : 'ltr';
+      } else {
+        return siteDir();
+      }
+    }
+  },
+
+  keyUp() {
+    if (Discourse.SiteSettings.support_mixed_text_direction) {
+      let val = this.value;
+      if (isRTL(val)) {
+        this.set('dir', 'rtl');
+      } else if (isLTR(val)) {
+        this.set('dir', 'ltr');
+      } else {
+        this.set('dir', siteDir());
+      }
+    }
+  },
 
   @computed("placeholderKey")
   placeholder(placeholderKey) {
diff --git a/app/assets/javascripts/discourse/helpers/category-link.js.es6 b/app/assets/javascripts/discourse/helpers/category-link.js.es6
index 336e25314ee..de7f73f5793 100644
--- a/app/assets/javascripts/discourse/helpers/category-link.js.es6
+++ b/app/assets/javascripts/discourse/helpers/category-link.js.es6
@@ -1,4 +1,5 @@
 import { registerUnbound } from 'discourse-common/lib/helpers';
+import { isRTL } from "discourse/lib/text-direction";
 import { iconHTML } from 'discourse-common/lib/icon-library';
 
 var get = Em.get,
@@ -38,6 +39,7 @@ export function categoryBadgeHTML(category, opts) {
   let color = get(category, 'color');
   let html = "";
   let parentCat = null;
+  let categoryDir = "";
 
   if (!opts.hideParent) {
     parentCat = Discourse.Category.findById(get(category, 'parent_category_id'));
@@ -66,10 +68,14 @@ export function categoryBadgeHTML(category, opts) {
 
   let categoryName = escapeExpression(get(category, 'name'));
 
+  if (Discourse.SiteSettings.support_mixed_text_direction) {
+    categoryDir = isRTL(categoryName) ? 'dir="rtl"' : 'dir="ltr"';
+  }
+
   if (restricted) {
-    html += `${iconHTML('lock')}<span>${categoryName}</span>`;
+    html += `${iconHTML('lock')}<span ${categoryDir}>${categoryName}</span>`;
   } else {
-    html += `<span>${categoryName}</span>`;
+    html += `<span ${categoryDir}>${categoryName}</span>`;
   }
   html += "</span>";
 
diff --git a/app/assets/javascripts/discourse/helpers/dir-span.js.es6 b/app/assets/javascripts/discourse/helpers/dir-span.js.es6
new file mode 100644
index 00000000000..6ce29e8f598
--- /dev/null
+++ b/app/assets/javascripts/discourse/helpers/dir-span.js.es6
@@ -0,0 +1,14 @@
+import { registerUnbound } from "discourse-common/lib/helpers";
+import { isRTL } from 'discourse/lib/text-direction';
+
+function setDir(text) {
+  if (Discourse.SiteSettings.support_mixed_text_direction) {
+    let textDir = isRTL(text) ? 'rtl' : 'ltr';
+    return `<span dir="${textDir}">${text}</span>`;
+  }
+  return text;
+}
+
+export default registerUnbound('dir-span', function(str) {
+  return new Handlebars.SafeString(setDir(str));
+});
diff --git a/app/assets/javascripts/discourse/initializers/post-decorations.js.es6 b/app/assets/javascripts/discourse/initializers/post-decorations.js.es6
index d17b2087acd..0cab9b554de 100644
--- a/app/assets/javascripts/discourse/initializers/post-decorations.js.es6
+++ b/app/assets/javascripts/discourse/initializers/post-decorations.js.es6
@@ -1,13 +1,18 @@
 import highlightSyntax from 'discourse/lib/highlight-syntax';
 import lightbox from 'discourse/lib/lightbox';
+import { setTextDirections } from "discourse/lib/text-direction";
 import { withPluginApi } from 'discourse/lib/plugin-api';
 
 export default {
   name: "post-decorations",
-  initialize() {
+  initialize(container) {
     withPluginApi('0.1', api => {
+      const siteSettings = container.lookup('site-settings:main');
       api.decorateCooked(highlightSyntax);
       api.decorateCooked(lightbox);
+      if (siteSettings.support_mixed_text_direction) {
+        api.decorateCooked(setTextDirections);
+      }
 
       api.decorateCooked($elem => {
         const players = $('audio', $elem);
diff --git a/app/assets/javascripts/discourse/lib/text-direction.js.es6 b/app/assets/javascripts/discourse/lib/text-direction.js.es6
new file mode 100644
index 00000000000..2a4b9da2c36
--- /dev/null
+++ b/app/assets/javascripts/discourse/lib/text-direction.js.es6
@@ -0,0 +1,28 @@
+const ltrChars = 'A-Za-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02B8\u0300-\u0590\u0800-\u1FFF\u2C00-\uFB1C\uFDFE-\uFE6F\uFEFD-\uFFFF';
+const rtlChars = '\u0591-\u07FF\uFB1D-\uFDFD\uFE70-\uFEFC';
+
+export function isRTL(text) {
+  const rtlDirCheck = new RegExp('^[^'+ltrChars+']*['+rtlChars+']');
+
+  return rtlDirCheck.test(text);
+}
+
+export function isLTR(text) {
+  const ltrDirCheck = new RegExp('^[^'+rtlChars+']*['+ltrChars+']');
+
+  return ltrDirCheck.test(text);
+}
+
+export function setTextDirections($elem) {
+  $elem.find('*').each((i, e) => {
+    let $e = $(e),
+      textContent = $e.text();
+    if (textContent) {
+      isRTL(textContent) ? $e.attr('dir', 'rtl') : $e.attr('dir', 'ltr');
+    }
+  });
+}
+
+export function siteDir() {
+  return $('html').hasClass('rtl') ? 'rtl' : 'ltr';
+}
diff --git a/app/assets/javascripts/discourse/models/topic.js.es6 b/app/assets/javascripts/discourse/models/topic.js.es6
index 69a4f9c27f2..4239398f053 100644
--- a/app/assets/javascripts/discourse/models/topic.js.es6
+++ b/app/assets/javascripts/discourse/models/topic.js.es6
@@ -3,6 +3,7 @@ import { flushMap } from 'discourse/models/store';
 import RestModel from 'discourse/models/rest';
 import { propertyEqual } from 'discourse/lib/computed';
 import { longDate } from 'discourse/lib/formatter';
+import { isRTL } from 'discourse/lib/text-direction';
 import computed from 'ember-addons/ember-computed-decorators';
 import ActionSummary from 'discourse/models/action-summary';
 import { popupAjaxError } from 'discourse/lib/ajax-error';
@@ -58,7 +59,13 @@ const Topic = RestModel.extend({
 
   @computed('fancy_title')
   fancyTitle(title) {
-    return censor(emojiUnescape(title || ""), Discourse.Site.currentProp('censored_words'));
+    let fancyTitle = censor(emojiUnescape(title || ""), Discourse.Site.currentProp('censored_words'));
+
+    if (Discourse.SiteSettings.support_mixed_text_direction) {
+      let titleDir = isRTL(title) ? 'rtl' : 'ltr';
+      return '<span dir="' + titleDir + '">' + fancyTitle + '</span>';
+    }
+    return fancyTitle;
   },
 
   // returns createdAt if there's no bumped date
diff --git a/app/assets/javascripts/discourse/templates/components/categories-only.hbs b/app/assets/javascripts/discourse/templates/components/categories-only.hbs
index f10712bb61e..2fa528e3a92 100644
--- a/app/assets/javascripts/discourse/templates/components/categories-only.hbs
+++ b/app/assets/javascripts/discourse/templates/components/categories-only.hbs
@@ -16,7 +16,7 @@
             <div>
               {{category-title-link category=c}}
               <div class="category-description">
-                {{{c.description_excerpt}}}
+                {{{dir-span c.description_excerpt}}}
               </div>
               <div class="clearfix"></div>
             </div>
diff --git a/app/assets/javascripts/discourse/templates/components/category-title-link.hbs b/app/assets/javascripts/discourse/templates/components/category-title-link.hbs
index fcb0bdeb071..3403e70d494 100644
--- a/app/assets/javascripts/discourse/templates/components/category-title-link.hbs
+++ b/app/assets/javascripts/discourse/templates/components/category-title-link.hbs
@@ -3,7 +3,7 @@
     {{d-icon 'lock'}}
   {{/if}}
 
-  <span class="category-name">{{category.name}}</span>
+  <span class="category-name">{{dir-span category.name}}</span>
 
   {{#if category.uploaded_logo.url}}
     <div>{{cdn-img src=category.uploaded_logo.url class="category-logo"}}</div>
diff --git a/app/assets/javascripts/discourse/templates/list/topic-excerpt.raw.hbs b/app/assets/javascripts/discourse/templates/list/topic-excerpt.raw.hbs
index 0a42a6a0c56..1c7b5eead0e 100644
--- a/app/assets/javascripts/discourse/templates/list/topic-excerpt.raw.hbs
+++ b/app/assets/javascripts/discourse/templates/list/topic-excerpt.raw.hbs
@@ -1,6 +1,6 @@
 {{#if topic.hasExcerpt}}
   <div class="topic-excerpt">
-    {{{topic.escapedExcerpt}}}
+    {{{dir-span topic.escapedExcerpt}}}
     {{#if topic.excerptTruncated}}
       <a href="{{topic.url}}">{{i18n 'read_more'}}</a>
     {{/if}}
diff --git a/app/assets/javascripts/discourse/templates/navigation/category.hbs b/app/assets/javascripts/discourse/templates/navigation/category.hbs
index d8dcac7040c..55c7e7ef849 100644
--- a/app/assets/javascripts/discourse/templates/navigation/category.hbs
+++ b/app/assets/javascripts/discourse/templates/navigation/category.hbs
@@ -5,7 +5,7 @@
     {{#if category.uploaded_logo.url}}
       {{cdn-img src=category.uploaded_logo.url class="category-logo"}}
       {{#if category.description}}
-        <p>{{{category.description}}}</p>
+        <p>{{{dir-span category.description}}}</p>
       {{/if}}
     {{/if}}
   </section>
diff --git a/app/assets/javascripts/select-kit/templates/components/category-row.hbs b/app/assets/javascripts/select-kit/templates/components/category-row.hbs
index 985fe9cd74a..85cdfd8f156 100644
--- a/app/assets/javascripts/select-kit/templates/components/category-row.hbs
+++ b/app/assets/javascripts/select-kit/templates/components/category-row.hbs
@@ -15,7 +15,7 @@
     {{/if}}
 
     {{#if shouldDisplayDescription}}
-      <div class="category-desc">{{{description}}}</div>
+      <div class="category-desc">{{{dir-span description}}}</div>
     {{/if}}
 {{else}}
   {{{label}}}
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index dc948cbbdb6..0edc451ef10 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -1278,6 +1278,7 @@ en:
       olist_title: "Numbered List"
       ulist_title: "Bulleted List"
       list_item: "List item"
+      toggle_direction: "Toggle Direction"
       help: "Markdown Editing Help"
       collapse: "minimize the composer panel"
       abandon: "close composer and discard draft"
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index d698d82fbab..a328a54a71a 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -966,6 +966,7 @@ en:
     default_locale: "The default language of this Discourse instance"
     allow_user_locale: "Allow users to choose their own language interface preference"
     set_locale_from_accept_language_header: "set interface language for anonymous users from their web browser's language headers. (EXPERIMENTAL, does not work with anonymous cache)"
+    support_mixed_text_direction: "Support mixed left-to-right and right-to-left text directions."
     min_post_length: "Minimum allowed post length in characters"
     min_first_post_length: "Minimum allowed first post (topic body) length in characters"
     min_private_message_post_length: "Minimum allowed post length in characters for messages"
diff --git a/config/site_settings.yml b/config/site_settings.yml
index e02399e1515..3fddeee679f 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -79,6 +79,9 @@ basic:
   set_locale_from_accept_language_header:
     default: false
     validator: "AllowUserLocaleEnabledValidator"
+  support_mixed_text_direction:
+    client: true
+    default: false
   categories_topics:
     default: 20
     min: 5