A slacker and a career-driven woman accidentally conceive a child after a one-night stand. As they try to make the relationship work, they must navigate the challenges of parenthood and their differences in lifestyle and maturity.
| Actor | Role |
|---|---|
 Seth RogenBen Stone | Ben Stone |
 Katherine HeiglAlison Scott | Alison Scott |
 Paul RuddPete | Pete |
 Leslie MannDebbie | Debbie |
 Jason SegelJason | Jason |
 Jay BaruchelJay | Jay |
 Jonah HillJonah | Jonah |
 Martin StarrMartin | Martin |
 Lo MutucJodi | Jodi |
 Iris ApatowCharlotte | Charlotte |
 Maude ApatowSadie | Sadie |
 Joanna KernsAlison's Mom | Alison's Mom |
 Harold RamisBen's Dad | Ben's Dad |
 Alan TudykJack | Jack |
 Kristen WiigJill | Jill |
 Bill HaderBrent | Brent |
 Ken JeongDr. Kuni | Dr. Kuni |
 Craig RobinsonClub Doorman | Club Doorman |
 Tim BagleyDr. Pellagrino | Dr. Pellagrino |
 Loudon Wainwright IIIDr. Howard | Dr. Howard |
| SStephanie MnookinDr. Howard's Nurse | Dr. Howard's Nurse |
 Adam ScottSamuel | Samuel |
 J.P. ManouxDr. Angelo | Dr. Angelo |
 Mo CollinsFemale Doctor | Female Doctor |
 B.J. NovakYoung Doctor | Young Doctor |
 Tami SagherWardrobe Lady | Wardrobe Lady |
 Brianna BrownAlison's Friend | Alison's Friend |
 Catherine ReitmanAlison's Friend | Alison's Friend |
 Nick ThuneAlison's Friend | Alison's Friend |
 Paul FeigFantasy Baseball Guy | Fantasy Baseball Guy |