Season one takes place between March and November 1960. It introduces the fictional advertising agency Sterling Cooper. The season begins with the new secretary, Peggy Olson, starting her first day with the firm. As the season unfolds, the mysterious backstory of enigmatic ad man Don Draper is revealed as are the growing confidence and success of Peggy Olson.

Season two takes place between February and October 1962, culminating with the Cuban Missile Crisis. It expands on Peggy's rise in the workplace and the marital strife between Don and Betty Draper as Don's infidelities further intrude on his family life. The second season also introduces an unknown acquaintance of Don Draper. Draper is corresponding by letter with this unseen acquaintance in secret.

Season three takes place six months after the conclusion of the second season and ends in December 1963. It chronicles the end of the "Camelot era" as the characters go through immense change in their professional and personal lives.

Season four takes place between November 1964 and October 1965. It is set at the new and considerably more modern advertising agency, Sterling Cooper Draper Pryce. The main narrative of the fourth season is driven by Don Draper's identity crisis. As Don falls deeper into existential despair, he begins regularly meeting with women of loose moral character and faces debilitating alcoholism.

Season 5 takes place between Memorial Day 1966 and spring 1967. The season explores Don Draper's new marriage to Megan, which leads him to ignore his work at the Sterling Cooper Draper Pryce advertising agency. Meanwhile, Lane, Pete, Roger, Joan, and Peggy learn that it is "every man for himself" in their personal and professional lives, as they each face painful new beginnings.

Season 6 takes place between December 1967 and November 1968.

The first part of season 7 begins in January 1969, several weeks after the Thanksgiving 1968 ending of season 6, and ends in July 1969, with characters dealing with the dynamics of lives and offices being split between New York and Los Angeles.