The plot is about Annie (Wiig), who suffers a series of misfortunes after being asked to serve as maid of honor for her best friend, Lillian, played by Maya Rudolph. Rose Byrne, Melissa McCarthy, Ellie Kemper, and Wendi McLendon-Covey co-star as Lillian's bridesmaids, with Chris O'Dowd, Rebel Wilson, Matt Lucas, Michael Hitchcock, Jon Hamm, and Jill Clayburgh, in her final movie role, in supporting roles.