diff --git a/src/lib/datepicker/calendar-body.html b/src/lib/datepicker/calendar-body.html
index 01f2684b77e..50b784bb8b5 100644
--- a/src/lib/datepicker/calendar-body.html
+++ b/src/lib/datepicker/calendar-body.html
@@ -35,6 +35,7 @@
       [class.mat-calendar-body-active]="_isActiveCell(rowIndex, colIndex)"
       [attr.aria-label]="item.ariaLabel"
       [attr.aria-disabled]="!item.enabled || null"
+      [attr.aria-selected]="selectedValue === item.value"
       (click)="_cellClicked(item)"
       [style.width.%]="100 / numCols"
       [style.paddingTop.%]="50 * cellAspectRatio / numCols"
diff --git a/src/lib/datepicker/calendar-body.spec.ts b/src/lib/datepicker/calendar-body.spec.ts
index ea5052d7b66..30ea688a378 100644
--- a/src/lib/datepicker/calendar-body.spec.ts
+++ b/src/lib/datepicker/calendar-body.spec.ts
@@ -23,21 +23,21 @@ describe('MatCalendarBody', () => {
     let fixture: ComponentFixture<StandardCalendarBody>;
     let testComponent: StandardCalendarBody;
     let calendarBodyNativeElement: Element;
-    let rowEls: NodeListOf<Element>;
-    let labelEls: NodeListOf<Element>;
-    let cellEls: NodeListOf<Element>;
+    let rowEls: Element[];
+    let labelEls: Element[];
+    let cellEls: Element[];
 
-    let refreshElementLists = () => {
-      rowEls = calendarBodyNativeElement.querySelectorAll('tr');
-      labelEls = calendarBodyNativeElement.querySelectorAll('.mat-calendar-body-label');
-      cellEls = calendarBodyNativeElement.querySelectorAll('.mat-calendar-body-cell');
-    };
+    function refreshElementLists() {
+      rowEls = Array.from(calendarBodyNativeElement.querySelectorAll('tr'));
+      labelEls = Array.from(calendarBodyNativeElement.querySelectorAll('.mat-calendar-body-label'));
+      cellEls = Array.from(calendarBodyNativeElement.querySelectorAll('.mat-calendar-body-cell'));
+    }
 
     beforeEach(() => {
       fixture = TestBed.createComponent(StandardCalendarBody);
       fixture.detectChanges();
 
-      let calendarBodyDebugElement = fixture.debugElement.query(By.directive(MatCalendarBody));
+      const calendarBodyDebugElement = fixture.debugElement.query(By.directive(MatCalendarBody));
       calendarBodyNativeElement = calendarBodyDebugElement.nativeElement;
       testComponent = fixture.componentInstance;
 
@@ -51,17 +51,26 @@ describe('MatCalendarBody', () => {
     });
 
     it('highlights today', () => {
-      let todayCell = calendarBodyNativeElement.querySelector('.mat-calendar-body-today')!;
+      const todayCell = calendarBodyNativeElement.querySelector('.mat-calendar-body-today')!;
       expect(todayCell).not.toBeNull();
       expect(todayCell.innerHTML.trim()).toBe('3');
     });
 
     it('highlights selected', () => {
-      let selectedCell = calendarBodyNativeElement.querySelector('.mat-calendar-body-selected')!;
+      const selectedCell = calendarBodyNativeElement.querySelector('.mat-calendar-body-selected')!;
       expect(selectedCell).not.toBeNull();
       expect(selectedCell.innerHTML.trim()).toBe('4');
     });
 
+    it('should set aria-selected correctly', () => {
+      const selectedCells = cellEls.filter(c => c.getAttribute('aria-selected') === 'true');
+      const deselectedCells = cellEls.filter(c => c.getAttribute('aria-selected') === 'false');
+
+      expect(selectedCells.length).toBe(1, 'Expected one cell to be marked as selected.');
+      expect(deselectedCells.length)
+          .toBe(cellEls.length - 1, 'Expected remaining cells to be marked as deselected.');
+    });
+
     it('places label in first row if space is available', () => {
       testComponent.rows[0] = testComponent.rows[0].slice(3);
       testComponent.rows = testComponent.rows.slice();
@@ -77,7 +86,7 @@ describe('MatCalendarBody', () => {
     });
 
     it('cell should be selected on click', () => {
-      let todayElement =
+      const todayElement =
           calendarBodyNativeElement.querySelector('.mat-calendar-body-today') as HTMLElement;
       todayElement.click();
       fixture.detectChanges();
@@ -96,20 +105,20 @@ describe('MatCalendarBody', () => {
     let fixture: ComponentFixture<CalendarBodyWithDisabledCells>;
     let testComponent: CalendarBodyWithDisabledCells;
     let calendarBodyNativeElement: Element;
-    let cellEls: NodeListOf<Element>;
+    let cellEls: HTMLElement[];
 
     beforeEach(() => {
       fixture = TestBed.createComponent(CalendarBodyWithDisabledCells);
       fixture.detectChanges();
 
-      let calendarBodyDebugElement = fixture.debugElement.query(By.directive(MatCalendarBody));
+      const calendarBodyDebugElement = fixture.debugElement.query(By.directive(MatCalendarBody));
       calendarBodyNativeElement = calendarBodyDebugElement.nativeElement;
       testComponent = fixture.componentInstance;
-      cellEls = calendarBodyNativeElement.querySelectorAll('.mat-calendar-body-cell');
+      cellEls = Array.from(calendarBodyNativeElement.querySelectorAll('.mat-calendar-body-cell'));
     });
 
     it('should only allow selection of disabled cells when allowDisabledSelection is true', () => {
-      (cellEls[0] as HTMLElement).click();
+      cellEls[0].click();
       fixture.detectChanges();
 
       expect(testComponent.selected).toBeFalsy();
@@ -117,7 +126,7 @@ describe('MatCalendarBody', () => {
       testComponent.allowDisabledSelection = true;
       fixture.detectChanges();
 
-      (cellEls[0] as HTMLElement).click();
+      cellEls[0].click();
       fixture.detectChanges();
 
       expect(testComponent.selected).toBe(1);