Muriel Heslop (Toni Collete) is jobless, has a low self-esteem and is obsessed with getting married to become successful. She lives in Porpoise Spit, a coastal resort, has no genuine friends and a dysfunctional family.
Muriel's father, Bill Heslop, is a corrupt small-town politician who can not understand why the rest of the family have trouble keeping up with him. Bill divides his life between his mistress Deidre, a cosmetics seller, and time spent tyrannizing and putting down Muriel and the rest of the Heslop household.
Betty, Muriel's mother, never seems to understand Bill or the rest of her family and is slowly disappearing without her family knowing. Dim Betty is drowning under an ocean of dirty dishes and when asked to give Muriel a blank check, she blankly responds, "How much for?"
Parents who don't get along and jobless, couch potato children who sit around all day watching sport on television, portray Australian family life in Muriel's Wedding. This negative portrayal also extends to a number of cases of adultery and family dysfunction.
Muriel comforts herself with ABBA records, dreaming of the white wedding that will turn her into another person. In one scene, at a nightclub named "Breakers", Muriel meets her so-called "friends" who proceed to tell her they don't like her because she is an embarrassment. These bimbo bitches tell Muriel she needs to "find friends on her own level." This scene is symbolic of the way Muriel is treated throughout the movie and the way she acts in return. Muriel is forever being told she is not good enough and is an embarrassment, which is why she tries to transform herself into a new person.
And so the story unfolds and the plot thickens. Muriel meets Rhonda (Rachael Griffiths) at Hibiscus Island