Ronseal is a British wood stain and preservative manufacturer, responsible for the "Does exactly what it says on the tin" phrase, an advertising slogan created by agency HHCL which has since entered popular culture.

The company, a wholly owned subsidiary of the Sherwin-Williams Company, is based in Chapeltown, Sheffield.

The original Ronseal products were developed in the 1950s by Ronuk Ltd, a manufacturer of wax polishes and wood stains based in Portslade, Brighton. Ronuk was purchased by Izal Ltd in 1960, itself owned by the Newton Chamber Group in Sheffield.

Known as Roncraft, it became a separate sales division of Izal in 1970 and was bought three years later by the Sterling Drug Company.

In 1989, Sterling was bought by Eastman Kodak until the multinational photographic company sold all of its do it yourself business to Forstmann Little & Co. in 1994. The New York-based investment bank renamed the company to Ronseal Ltd and sold it to Sherwin-Williams in 1997.