Effie Sylvia Marsh (née Pepin; 9 June 1868 - 20 March 1979) was an American woman believed to be the oldest resident in Iowa at the time of her death. She was born in Cresco, Iowa on 9 June 1868 as the daughter of Abner and Esther Bly Pepin. She grew up in Iowa and married John Marsh in Fredricksburg, Iowa on 5 December 1901. The couple had two children. She was widowed in 1953. Effie Marsh died in Waverly, Iowa on 20 March 1979, aged 110 years, 284 days. Her case is currently pending.