Leo Fitz is a character in the Agents of S.H.I.E.L.D. series. He is a Scottish-born S.H.I.E.L.D. agent and scientist. He is a genius engineer, and was one of the youngest and most prominent members of S.H.I.E.L.D.'s Sci-Tech division, and inseparable from his research partner and best friend, Jemma Simmons.