"The Disappearance of Lady Frances Carfax" is one of the 56 Sherlock Holmes short stories written by Sir Arthur Conan Doyle. It is one of the eight stories in the cycle collected as His Last Bow, and one of the few stories in which for much of the plot Watson must act alone and try his best with Holmes left in the background.

Holmes sends Dr. Watson to Lausanne to investigate Lady Frances Carfax's disappearance since he himself is too busy in London. Lady Frances is a lone, unwed woman denied a rich inheritance on account of her sex. She does, however, carry valuable jewels with her. It is also her habit to write to her old governess, Miss Dobney, every other week, but for the past five weeks, there has not been a word from her. She has left the Hôtel National for parts unknown. Her last two bank transactions were cheques, one to pay her hotel bill, and another for £50 to her maid, Miss Marie Devine.