Serta is an American company based in Hoffman Estates, Illinois that specializes in developing and manufacturing mattresses. It was founded in 1931. Serta is the largest mattress brand in the United States, and offers three main types of mattresses – traditional inner spring, gel-infused memory foam, and hybrid mattresses which combine both. Serta products are used extensively in the lodging industry, with Hilton Worldwide and Wyndham Worldwide among its customers. Serta mattresses are also offered on cable home shopping channel ShopNBC.

The company is famous for its “Counting Sheep” advertising campaign which were animated by Aardman Animations and first created in 2000.