She was always on hand to help Steve in Captain America: The First Avengers. And was left heartbroken when he crashed Red Skull's plane into the Artic at the end...
But now the British secret agent is set to star in her very own TV series.
Marvel are preparing to develop a TV series based on Hayley Atwell's ass-kicking agent, who manages to complete complicated missions without smudging her lipstick or mucking up her victory rolls.
The Restless, Black Mirror and Life of Crime actress, who stars in upcoming film Captain America: The Winter Soldier, appears in a Marvel One-Shot short as part of the blu-ray extras for Iron Man 3, which sees Peggy Carter outshine the stuffy men in her department. The new TV series is said to have been inspired by the short.
The project is "in very early stages" according to Deadline, who also stress that "it is unclear if Atwell would reprise her role if Agent Carter comes to fruition."
See Peggy Carter in action:
Upcoming Marvel series The Agents of S.H.I.E.L.D is an Avengers Assemble spin-off, also inspired by a DVD extra. The series, which aired on ABC in America, is coming to Channel 4 on 27 September.
Watch a trailer for Agents of S.H.I.E.L.D: