diff --git a/client/gutenberg/editor/calypso-store/actions.js b/client/gutenberg/editor/calypso-store/actions.js
new file mode 100644
index 000000000000..b8f64153d19c
--- /dev/null
+++ b/client/gutenberg/editor/calypso-store/actions.js
@@ -0,0 +1,4 @@
+export const setSelectedSiteId = selectedSiteId => ( {
+	type: 'GUTENLYPSO_SELECTED_SITE_ID_SET',
+	selectedSiteId,
+} );
diff --git a/client/gutenberg/editor/calypso-store/index.js b/client/gutenberg/editor/calypso-store/index.js
new file mode 100644
index 000000000000..c30039758e3c
--- /dev/null
+++ b/client/gutenberg/editor/calypso-store/index.js
@@ -0,0 +1,19 @@
+/**
+ * WordPress Dependencies
+ */
+import { registerStore } from '@wordpress/data';
+
+/**
+ * Internal dependencies
+ */
+import reducer from './reducer';
+import * as actions from './actions';
+import * as selectors from './selectors';
+
+const store = registerStore( 'gutenberg/calypso', {
+	reducer,
+	actions,
+	selectors,
+} );
+
+export default store;
diff --git a/client/gutenberg/editor/calypso-store/reducer.js b/client/gutenberg/editor/calypso-store/reducer.js
new file mode 100644
index 000000000000..877266bd5264
--- /dev/null
+++ b/client/gutenberg/editor/calypso-store/reducer.js
@@ -0,0 +1,10 @@
+/* eslint-disable wpcalypso/import-docblock */
+/**
+ * WordPress dependencies
+ */
+import { combineReducers } from '@wordpress/data';
+
+const selectedSiteId = ( state = null, action ) =>
+	'GUTENLYPSO_SELECTED_SITE_ID_SET' === action.type ? action.selectedSiteId : state;
+
+export default combineReducers( { selectedSiteId } );
diff --git a/client/gutenberg/editor/calypso-store/selectors.js b/client/gutenberg/editor/calypso-store/selectors.js
new file mode 100644
index 000000000000..34bd270208c2
--- /dev/null
+++ b/client/gutenberg/editor/calypso-store/selectors.js
@@ -0,0 +1 @@
+export const getSelectedSiteId = state => state.selectedSiteId;
diff --git a/client/gutenberg/editor/controller.js b/client/gutenberg/editor/controller.js
index 755402a27610..f871a69bce88 100644
--- a/client/gutenberg/editor/controller.js
+++ b/client/gutenberg/editor/controller.js
@@ -12,7 +12,7 @@ import { has, set, uniqueId } from 'lodash';
  * WordPress dependencies
  */
 import { setLocaleData } from '@wordpress/i18n';
-import { dispatch } from '@wordpress/data';
+import { dispatch, select } from '@wordpress/data';
 
 /**
  * Internal dependencies
@@ -110,6 +110,22 @@ export const loadGutenbergBlockAvailability = store => {
 	} );
 };
 
+export const resetGutenbergState = ( registry, selectedSiteId ) => {
+	// Always reset core/editor, core/notices, and other UI parts
+	registry.reset( 'core/editor' );
+	registry.reset( 'core/notices' );
+	dispatch( 'core/edit-post' ).closePublishSidebar();
+	dispatch( 'core/edit-post' ).closeModal();
+
+	// Only reset core/data on site change
+	const previousGutenbergSiteId = select( 'gutenberg/calypso' ).getSelectedSiteId();
+
+	if ( !! previousGutenbergSiteId && previousGutenbergSiteId !== selectedSiteId ) {
+		registry.resetCoreResolvers();
+	}
+	dispatch( 'gutenberg/calypso' ).setSelectedSiteId( selectedSiteId );
+};
+
 export const redirect = ( { store: { getState } }, next ) => {
 	const state = getState();
 	const siteId = getSelectedSiteId( state );
@@ -140,10 +156,7 @@ export const post = async ( context, next ) => {
 
 		const { Editor, registry } = initGutenberg( userId, context.store );
 
-		// Reset the Gutenberg state
-		registry.reset();
-		dispatch( 'core/edit-post' ).closePublishSidebar();
-		dispatch( 'core/edit-post' ).closeModal();
+		resetGutenbergState( registry, siteId );
 
 		return props => (
 			<Editor { ...{ siteId, postId, postType, uniqueDraftKey, isDemoContent, ...props } } />
diff --git a/client/gutenberg/editor/init.js b/client/gutenberg/editor/init.js
index 34e46fc4e642..d90acd3b559a 100644
--- a/client/gutenberg/editor/init.js
+++ b/client/gutenberg/editor/init.js
@@ -34,26 +34,34 @@ const addResetToRegistry = registry => {
 		window.gutenbergState = () => mapValues( registry.stores, ( { store } ) => store.getState() );
 	}
 
-	const resettableStores = [ 'core/editor', 'core/notices' ];
-
 	const stores = [];
 	return {
 		registerStore( namespace, options ) {
-			let store;
-			if ( -1 === resettableStores.indexOf( namespace ) ) {
-				store = registry.registerStore( namespace, options );
-			} else {
-				store = registry.registerStore( namespace, {
-					...options,
-					reducer: ( state, action ) =>
-						options.reducer( 'GUTENLYPSO_RESET' === action.type ? undefined : state, action ),
-				} );
-			}
+			const store = registry.registerStore( namespace, {
+				...options,
+				reducer: ( state, action ) => {
+					if ( 'GUTENLYPSO_RESET' === action.type && namespace === action.namespace ) {
+						debug( `Resetting ${ namespace } store` );
+						return options.reducer( undefined, action );
+					}
+					return options.reducer( state, action );
+				},
+			} );
 			stores.push( store );
 			return store;
 		},
-		reset() {
-			stores.forEach( store => store.dispatch( { type: 'GUTENLYPSO_RESET' } ) );
+		reset( namespace ) {
+			stores.forEach( store => store.dispatch( { type: 'GUTENLYPSO_RESET', namespace } ) );
+		},
+		resetCoreResolvers() {
+			// @see https://github.com/WordPress/gutenberg/blob/e1092c0d0b75fe53ab57bc6c4cc9e32cb2e74e40/packages/data/src/resolvers-cache-middleware.js#L14-L34
+			const resolvers = registry.select( 'core/data' ).getCachedResolvers( 'core' );
+			debug( `Resetting core store resolvers: ${ Object.keys( resolvers ).toString() }` );
+			Object.entries( resolvers ).forEach( ( [ selectorName, resolversByArgs ] ) => {
+				resolversByArgs.forEach( ( value, args ) => {
+					registry.dispatch( 'core/data' ).invalidateResolution( 'core', selectorName, args );
+				} );
+			} );
 		},
 	};
 };
@@ -63,12 +71,15 @@ const addResetToRegistry = registry => {
 export const initGutenberg = once( ( userId, store ) => {
 	debug( 'Starting Gutenberg editor initialization...' );
 
+	const registry = use( addResetToRegistry );
+
 	debug( 'Registering data plugins' );
 	const storageKey = 'WP_DATA_USER_' + userId;
 	use( plugins.persistence, { storageKey: storageKey } );
 	use( plugins.controls );
 
-	const registry = use( addResetToRegistry );
+	debug( 'Initializing gutenberg/calypso store' );
+	require( 'gutenberg/editor/calypso-store' );
 
 	// We need to ensure that core-data is loaded after the data plugins have been registered.
 	debug( 'Initializing core-data store' );