The Hay Wain is an oil on canvas painting by John Constable. It was finished in 1821 and shows a hay wain near Flatford Mill on the River Stour at Flatford , Suffolk.

It is revered as one of the greatest British paintings, but when it was originally exhibited at the Royal Academy in 1821 it failed to find a buyer. It started gaining respect after Charles X of France awarded it a gold medal during a presentation of other Constable paintings.