John Graham Robertson (14 February 1859 – 24 October 1940) was a tenor who made early London and New York appearances in Shakespeare with Henry Irving's company. He served as principal tenor of the D'Oyly Carte Opera Company in several Gilbert and Sullivan operas at the Savoy Theatre during 1887 and 1888. Robertson produced and directed the opera Mignonette in 1889 before creating the role of Alfredo in the comic opera The Mountebanks in 1892. He concentrated on concert singing from the 1890s into the 20th century.