Ward lived in London, UK, at the end of his life. He died in Nuffield Hospital in London of heart failure at age 90.

His father was the American sculptor, Frederick William MacMonnies.

Married Dolores Ward;

He and his wife had a daughter, Sylvia Ward Sawyer, of Chestertown, MD; a son, Robertson Ward Jr., of Boston, MA.

Ward's firm became well known after the 1940s for its design of resorts in the Caribbean.