Your morning coffee habit just became a little sweeter. Dunkin Donuts is supplying a free classic donut with the purchase of a beverage in honor of National Donut Day on Friday, June 3, 2022. Choose any classic donut flavor, including glazed, jelly-filled, cake, Boston Kreme, chocolate glazed and more. The offer is good all day, while supplies last. Check out participating Dunkin Donut locations.