Fox as Mike Flaherty. Deputy Mayor of New York and a lothario , Flaherty lives in a New York City apartment and is constantly juggling his personal life and his job, trying to maintain a healthy balance between the two. Flaherty leaves the mayor's office at the end of season four, after taking the hit for an unknown mob connection the Mayor had Fox left the series due to his battle with Parkinson's disease , but returns during the first three episodes of the sixth season, culminating in his marriage.
Carla Gugino as Ashley Schaeffer, a journalist and romantic interest for Mike during the first 12 episodes. She was written out when the show started to focus more on the workplace, but returned for one episode in season three. A known cheapskate and gullible member of the group, he is often the victim of practical jokes or slip-ups at City Hall.
During the show, he marries Claudia Sachs, who in season five leaves him to become a nun. By the end of the show, he moves into an apartment across the hall from Carter and Stuart.
He is shallow and sex-crazed, although he is unsuccessful at maintaining a relationship. Early on in the series, he moves into an apartment with Carter, which generates a clash of personalities as he is a homophobe and is generally wary of Carter's dog and his high-strung lifestyle, though they eventually become best friends.
His character was met with positive reaction because of his portrayal as a prominent gay black character in a TV series. Carter owns a suicidal old dog named Rags. Near the end of the show, Rags dies, and in the same season, Carter decides he will adopt a baby, which he does in the final episode, a boy, named Sam. She is promiscuous and outgoing and often dates unreliable men. She develops an on-again-off-again relationship with Mike. She leaves after season four for unknown reasons.
He is shown to be nervous and paranoid, and early in the show has a crush on Nikki. While he is first the speech writer, during season four, he is fired in favor of Caitlin being hired as marketing campaigner, and James is hired as Mike's secretary, although he is led to believe his position is as 'Deputy Deputy Mayor'. He also leaves after season four for unknown reasons. At one point during the show, he runs for the Senate, although between seasons he apparently decided not to.
At the beginning of the show, he is married, although he gets divorced during the show's run and his now ex-wife writes a tell-all book about life with the Mayor. He develops a relationship with his secretary Janelle during season three. During the final season, he develops a relationship with Judge Claire Simmons, played by Farrah Fawcett , but she dumps him when she reveals she does not want to live life in the public eye like the mayor.
Victoria Dillard , as Janelle Cooper, Mike's secretary during the first season, promoted to the Mayor's secretary during the second. She develops a relationship with the Mayor during season three. The characters Janelle, James and Nikki were written out of the show with no explanation when actors Dillard, Chaplin, and Britton left the show after season four because of the show's move from New York to Los Angeles.
Jennifer Esposito , as Stacey Paterno, who replaced Janelle as Mike's secretary for seasons two and three, after Janelle became the Mayor's secretary. She is from Brooklyn and is shown to be very outgoing, much like Nikki. She left the cast after advice from director Spike Lee.
Fox's workload after he announced he had Parkinson's disease. She is brought onto the staff as marketing campaigner, and takes James's old desk, while James becomes Mike's secretary.
She becomes romantically involved with both leads by the end of each of their respective tenures on the show. Charlie Sheen as Charlie Crawford, Mike's replacement for the final two seasons. He, too, is a lothario and at first struggles to keep his difficult past from getting in the way of his new job.
He eventually becomes romantically involved with Caitlin by the end of the series' run. He is also romantically involved with Jennifer Duncan, played by Sheen's real-life partner at the time, Denise Richards. His father is also played by Sheen's real-life father Martin Sheen. Lana Parrilla , as Angie Ordonez, Charlie's secretary. She was only featured in season five, as Parrilla left following the season, thinking her character was underused.
No secretary is shown during season six, and her desk is left empty. Some of the cast are shown using it, albeit not permanently, implying Charlie is no longer using a secretary and the desk is filling other roles.