Agent 13 may refer to:
- Peggy Carter - One of the most prominent agents of the Strategic Scientific Reserve (SSR) before, during, and after World War II. She is one of the founders of S.H.I.E.L.D..
- Sharon Carter - A former agent of S.H.I.E.L.D. undercover as the neighbour of Steve Rogers and the niece of Peggy Carter.
- Agent (Code 13) - An unnamed female S.H.I.E.L.D. Agent that awoke Steve Rogers in New York City after he was recovered from the crash site of the Valkyrie.