Muriel Heslop (Toni Collette), who loves the music of ABBA, is the target of ridicule by her shallow snobby friends Tania, Cheryl, Nicole and Janine, for her awkwardness, fashion sense, and embarrassing antics. She also is a perpetual daydreamer who yearns for a glamorous wedding to a man who will help get her out of the dead-end seaside tourist town of Porpoise Spit, improve her personal life, and free her from her domineering father, Bill (Bill Hunter), a corrupt politician who verbally lashes out at his subservient and depressed wife, Betty, and their unambitious children at every opportunity. Muriel attends the wedding of Tania and Chook. During the wedding reception Muriel sees Nicole and Chook having sex in a room. Chook's cousin Dianna calls the police on Muriel for stealing a dress that she is currently wearing at the wedding. Dianna witnessed Muriel stealing the dress at a store before the wedding. Muriel is escorted out the wedding reception by police. Soon after, Muriel's "friends" break off their friendship with her and plan a holiday to Hibiscus Island without her to cheer up Tania, who found out that Chook has cheated on her with another woman called Rose Biggs. Tania doesn't know that Chook had also been cheating on her with Nicole.