Mary Isobel ` Mollie ' Sugden ( 21 July 1922 â `` 1 July 2009 ) was an English comedy actress best known for playing saleswoman Mrs. Slocombe in the popular British sitcom Are You Being Served ? Isabel Mary ` Mollie ' Sugden ( 21 July 1922 -- 1 July 2009 ) was an English comedy actress best known for portraying the saleswoman Mrs. Slocombe in the British sitcom Are You Being Served ?