The revival, directed by Lindsay Posner, will tour in September and October before moving to the West End. Relatively Speaking centers on a love triangle between a pair of young lovers and an older married man.
West End dates and additional information will be announced in the coming weeks.
Kendal starred in the original production of Ayckbourn's The Norman Conquests, as well as Mrs. Warren's Profession and The Last Cigarette. Tointon was last seen in Ayckbourn's Absent Friends and starred opposite Rupert Everett in Pygmalion. Coy's credits include Much Ado About Nothing, opposite David Tennant and Catherine Tate.