[4] Oswald Yorke first performed on stage in 1884 and later as a member of a company headed by British actor Sir Francis Robert Benson.
[9][10] In October 1900, he played an attaché with the French Embassy in The Eaglett, an adaptation of Edmond Rostand's L’Aiglon by Louis Napoleon Parker that starred Maude Adams.
[11] By the next year, Yorke became associated with the Empire Theatre on Broadway, first appearing as Lieutenant Sir Walter Mannering opposite John Drew and Guy Standing in Roger Marshall's The Second in Command.
Yorke was Black Dog in a 1915 adaption of Robert Louis Stevenson's Treasure Island; Mr. Breen in the 1931 comedy "The Social Register" and Carter Hibbarb in George S. Kaufman's 1938 success, First Lady.
[14] During World War I, Yorke was put in charge of the entertainment of soldiers attached to the American Expeditionary Force in France.
Around that time, the two were performing in a return engagement of Charles Frohman's production Mice and Men, a comedy by Madeleine Lucette Ryley.