The cast of a television series are the actors who play the show's characters. The starring cast are those who are permanent members of the cast and are billed in the opening credits of each episode.
Starring cast
- Kelsey Grammer as Tom Kane, the mayor of Chicago
- Connie Nielsen as Meredith Kane, Tom Kane's wife
- Kathleen Robertson as Kitty O'Neill, Tom Kane's personal aide
- Hannah Ware as Emma Kane, Tom Kane's estranged daughter
- Jeff Hephner as Ben Zajac, Illinois State Treasurer and candidate for Governor of Illinois
Recurring cast
- Martin Donovan as Ezra Stone, Tom Kane's senior political advisor
- Francis Guinan as McCall Cullen, Governor of Illinois, who is running for re-election
- Rotimi Akinosho as Darius, a drug dealer who Emma Kane is fascinated by
- Karen Aldridge as Dr Ella Harris, Tom Kane's neurologist
- Troy Garity as Sam Miller, a political journalist working for The Sentinel
- Jennifer Mudge as Debra Whitehead, care-taker/nurse to Tom Kane's father-in-law
- Ricardo Gutierrez as Lalo Mata, an Alderman serving on the Chicago City Council, representing the 30th ward
- James Vincent Meredith as Ross, an Alderman serving on the Chicago City Council, from the South Side
- Joe Minoso as Moco Ruiz, the head of a construction company working on the airport expansion ordered by Mayor Kane