"The Rummy Affair of Old Biffy" is a short story by P. G. Wodehouse, and features the young gentleman Bertie Wooster and his valet Jeeves. The story was published in the Saturday Evening Post in the United States in September 1924, and in The Strand Magazine in the United Kingdom in October 1924. The story was also included in the 1925 collection Carry On, Jeeves.

Jeeves is a fictional character in a series of comedic short stories and novels by English author P. G. Wodehouse. Jeeves is the highly competent valet of a wealthy and idle young Londoner named Bertie Wooster. First appearing in print in 1915, Jeeves continued to feature in Wodehouse's work until his last completed novel Aunts Aren't Gentlemen in 1974, a span of 60 years.