Bakers •
Steve Martin as Tom Baker, the patriarch of the Baker family and retired football coach. •
Bonnie Hunt as Kate Gilbreth-Baker, the matriarch of the Baker family and Tom's wife who provides the opening narration. •
Piper Perabo as Nora Baker-McNulty, Tom and Kate's first daughter, Bud's wife, and Baby Tom's mother. •
Tom Welling as Charlie Baker, Tom and Kate's first son who becomes a
mechanic in order to pay off his college tuition. •
Hilary Duff as Lorraine Baker, Tom and Kate's second daughter who is planning to move to New York so that she can intern at
Allure magazine. •
Kevin G. Schmidt as Henry Baker, Tom and Kate's second son. •
Alyson Stoner as Sarah Baker, Tom and Kate's third daughter. •
Jacob Smith as Jake Baker, Tom and Kate's third son. • Forrest Landis as Mark Baker, Tom and Kate's fourth son. •
Liliana Mumy as Jessica Baker, Tom and Kate's fourth daughter and Kim's fraternal twin sister. •
Morgan York as Kim Baker, Tom and Kate's fifth daughter and Jessica's fraternal twin sister. •
Blake Woodruff as Mike Baker, Tom and Kate's fifth son. •
Brent Kinsman as Nigel Baker, Tom and Kate's sixth son and Kyle's identical twin brother. •
Shane Kinsman as Kyle Baker, Tom and Kate's seventh son and Nigel's identical twin brother.
Murtaughs •
Eugene Levy as Jimmy Murtaugh, the patriarch of the Murtaugh family who is an old rival of Tom. •
Carmen Electra as Sarina Murtaugh, the matriarch of the Murtaugh family and Jimmy's
trophy wife. •
Shawn Roberts as Calvin Murtaugh, Jimmy's first son who is a student at
Yale University. •
Jaime King as Anne Murtaugh, Jimmy's first daughter who becomes Charlie's love interest. She is hiding a
lower-back tattoo of a butterfly from her father as an act of rebellion. •
Robbie Amell as Daniel Murtaugh, Jimmy's second son. • Melanie Tonello as Becky Murtaugh, Jimmy's second daughter. •
Taylor Lautner as Elliot Murtaugh, Jimmy's third son who becomes Sarah's love interest. • Courtney Fitzpatrick as Lisa Murtaugh, Jimmy's third daughter and Robin's identical twin sister. • Madison Fitzpatrick as Robin Murtaugh, Jimmy's fourth daughter and Lisa's identical twin sister. •
Alexander Conti as Kenneth "Kenny" Murtaugh, Jimmy's fourth son.
Others •
Jonathan Bennett as Bud McNulty, Nora's husband, Tom and Kate's son-in-law, Baby Tom's father and the Baker kids' brother-in-law. •
Peter Keleghan as Mike Romanow, Jimmy's neighbor and friend who is the owner of the old cabin at Lake Winnetka that the Baker family rents and is also the emcee of the Annual Labor Day Family Cup. • William Copeland as the Commodore The director of the first film and producer of the sequel,
Shawn Levy, has a cameo as a hospital intern.
Ben Falcone appears as a cinema customer who gets upset with Tom and Jimmy's quarrel. ==Soundtrack==