diff --git a/src/components/structures/MessagePanel.js b/src/components/structures/MessagePanel.js
index b0f6699bc1..2037217710 100644
--- a/src/components/structures/MessagePanel.js
+++ b/src/components/structures/MessagePanel.js
@@ -92,6 +92,9 @@ module.exports = React.createClass({
 
         // show timestamps always
         alwaysShowTimestamps: PropTypes.bool,
+
+        // helper function to access relations for an event
+        getRelationsForEvent: PropTypes.func,
     },
 
     componentWillMount: function() {
@@ -529,6 +532,7 @@ module.exports = React.createClass({
                     permalinkCreator={this.props.permalinkCreator}
                     last={last}
                     isSelectedEvent={highlight}
+                    getRelationsForEvent={this.props.getRelationsForEvent}
                 />
             </li>,
         );
diff --git a/src/components/structures/TimelinePanel.js b/src/components/structures/TimelinePanel.js
index e065c5719e..17a062be98 100644
--- a/src/components/structures/TimelinePanel.js
+++ b/src/components/structures/TimelinePanel.js
@@ -1168,6 +1168,10 @@ const TimelinePanel = React.createClass({
         });
     },
 
+    getRelationsForEvent(...args) {
+        return this.props.timelineSet.getRelationsForEvent(...args);
+    },
+
     render: function() {
         const MessagePanel = sdk.getComponent("structures.MessagePanel");
         const Loader = sdk.getComponent("elements.Spinner");
@@ -1239,6 +1243,7 @@ const TimelinePanel = React.createClass({
                 className={this.props.className}
                 tileShape={this.props.tileShape}
                 resizeNotifier={this.props.resizeNotifier}
+                getRelationsForEvent={this.getRelationsForEvent}
             />
         );
     },
diff --git a/src/components/views/messages/MessageActionBar.js b/src/components/views/messages/MessageActionBar.js
index 9a482c9e6e..d2ac9adcf0 100644
--- a/src/components/views/messages/MessageActionBar.js
+++ b/src/components/views/messages/MessageActionBar.js
@@ -28,6 +28,8 @@ import { isContentActionable } from '../../../utils/EventUtils';
 export default class MessageActionBar extends React.PureComponent {
     static propTypes = {
         mxEvent: PropTypes.object.isRequired,
+        // The Relations model from the JS SDK for reactions to `mxEvent`
+        reactions: PropTypes.object,
         permalinkCreator: PropTypes.object,
         getTile: PropTypes.func,
         getReplyThread: PropTypes.func,
@@ -113,6 +115,7 @@ export default class MessageActionBar extends React.PureComponent {
         return <ReactionDimension
             title={_t("Agree or Disagree")}
             options={options}
+            reactions={this.props.reactions}
         />;
     }
 
@@ -135,6 +138,7 @@ export default class MessageActionBar extends React.PureComponent {
         return <ReactionDimension
             title={_t("Like or Dislike")}
             options={options}
+            reactions={this.props.reactions}
         />;
     }
 
diff --git a/src/components/views/messages/ReactionDimension.js b/src/components/views/messages/ReactionDimension.js
index 3b72aabe15..675d99e187 100644
--- a/src/components/views/messages/ReactionDimension.js
+++ b/src/components/views/messages/ReactionDimension.js
@@ -18,20 +18,56 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import classNames from 'classnames';
 
+import MatrixClientPeg from '../../../MatrixClientPeg';
+
 export default class ReactionDimension extends React.PureComponent {
     static propTypes = {
         options: PropTypes.array.isRequired,
         title: PropTypes.string,
+        // The Relations model from the JS SDK for reactions
+        reactions: PropTypes.object,
     };
 
     constructor(props) {
         super(props);
 
         this.state = {
-            selected: null,
+            selected: this.getInitialSelection(),
         };
     }
 
+    getInitialSelection() {
+        const myReactions = this.getMyReactions();
+        if (!myReactions) {
+            return null;
+        }
+        const { options } = this.props;
+        let selected = null;
+        for (const { key, content } of options) {
+            const reactionExists = myReactions.some(mxEvent => {
+                return mxEvent.getContent()["m.relates_to"].key === content;
+            });
+            if (reactionExists) {
+                if (selected) {
+                    // If there are multiple selected values (only expected to occur via
+                    // non-Riot clients), then act as if none are selected.
+                    return null;
+                }
+                selected = key;
+            }
+        }
+        return selected;
+    }
+
+    getMyReactions() {
+        const reactions = this.props.reactions;
+        if (!reactions) {
+            return null;
+        }
+        const userId = MatrixClientPeg.get().getUserId();
+        return reactions.getAnnotationsBySender()[userId];
+    }
+
     onOptionClick = (ev) => {
         const { key } = ev.target.dataset;
         this.toggleDimensionValue(key);
diff --git a/src/components/views/messages/ReactionsRow.js b/src/components/views/messages/ReactionsRow.js
index a4299b9853..7242fa9144 100644
--- a/src/components/views/messages/ReactionsRow.js
+++ b/src/components/views/messages/ReactionsRow.js
@@ -20,37 +20,24 @@ import PropTypes from 'prop-types';
 import sdk from '../../../index';
 import { isContentActionable } from '../../../utils/EventUtils';
 
-// TODO: Actually load reactions from the timeline
-// Since we don't yet load reactions, let's inject some dummy data for testing the UI
-// only. The UI assumes these are already sorted into the order we want to present,
-// presumably highest vote first.
-const SAMPLE_REACTIONS = {
-    "👍": 4,
-    "👎": 2,
-    "🙂": 1,
-};
-
 export default class ReactionsRow extends React.PureComponent {
     static propTypes = {
         // The event we're displaying reactions for
         mxEvent: PropTypes.object.isRequired,
+        // The Relations model from the JS SDK for reactions to `mxEvent`
+        reactions: PropTypes.object,
     }
 
     render() {
-        const { mxEvent } = this.props;
+        const { mxEvent, reactions } = this.props;
 
-        if (!isContentActionable(mxEvent)) {
-            return null;
-        }
-
-        const content = mxEvent.getContent();
-        // TODO: Remove this once we load real reactions
-        if (!content.body || content.body !== "reactions test") {
+        if (!reactions || !isContentActionable(mxEvent)) {
             return null;
         }
 
         const ReactionsRowButton = sdk.getComponent('messages.ReactionsRowButton');
-        const items = Object.entries(SAMPLE_REACTIONS).map(([content, count]) => {
+        const items = reactions.getSortedAnnotationsByKey().map(([content, events]) => {
+            const count = events.length;
             return <ReactionsRowButton
                 key={content}
                 content={content}
diff --git a/src/components/views/rooms/EventTile.js b/src/components/views/rooms/EventTile.js
index 59025bf431..d40dd5a77c 100644
--- a/src/components/views/rooms/EventTile.js
+++ b/src/components/views/rooms/EventTile.js
@@ -159,6 +159,9 @@ module.exports = withMatrixClient(React.createClass({
 
         // show twelve hour timestamps
         isTwelveHour: PropTypes.bool,
+
+        // helper function to access relations for an event
+        getRelationsForEvent: PropTypes.func,
     },
 
     getDefaultProps: function() {
@@ -472,6 +475,17 @@ module.exports = withMatrixClient(React.createClass({
         return this.refs.replyThread;
     },
 
+    getReactions() {
+        if (
+            !SettingsStore.isFeatureEnabled("feature_reactions") ||
+            !this.props.getRelationsForEvent
+        ) {
+            return null;
+        }
+        const eventId = this.props.mxEvent.getId();
+        return this.props.getRelationsForEvent(eventId, "m.annotation", "m.reaction");
+    },
+
     render: function() {
         const MessageTimestamp = sdk.getComponent('messages.MessageTimestamp');
         const SenderProfile = sdk.getComponent('messages.SenderProfile');
@@ -584,9 +598,11 @@ module.exports = withMatrixClient(React.createClass({
             }
         }
 
+        const reactions = this.getReactions();
         const MessageActionBar = sdk.getComponent('messages.MessageActionBar');
         const actionBar = <MessageActionBar
             mxEvent={this.props.mxEvent}
+            reactions={reactions}
             permalinkCreator={this.props.permalinkCreator}
             getTile={this.getTile}
             getReplyThread={this.getReplyThread}
@@ -630,11 +646,12 @@ module.exports = withMatrixClient(React.createClass({
                 <ToolTipButton helpText={keyRequestHelpText} />
             </div> : null;
 
-        let reactions;
+        let reactionsRow;
         if (SettingsStore.isFeatureEnabled("feature_reactions")) {
             const ReactionsRow = sdk.getComponent('messages.ReactionsRow');
-            reactions = <ReactionsRow
+            reactionsRow = <ReactionsRow
                 mxEvent={this.props.mxEvent}
+                reactions={reactions}
             />;
         }
 
@@ -750,7 +767,7 @@ module.exports = withMatrixClient(React.createClass({
                                            showUrlPreview={this.props.showUrlPreview}
                                            onHeightChanged={this.props.onHeightChanged} />
                             { keyRequestInfo }
-                            { reactions }
+                            { reactionsRow }
                             { actionBar }
                         </div>
                         {