Donovan Donaly, portrayed by Geoffrey Rush, is a soap opera producer who unexpectedly returns home early, only to discover his wife Bonnie, played by Stacey Travis, engaging with her ex-boyfriend Ollie, a pool cleaner, despite the fact that the Donalys do not own a pool. Enter Miles Massey, played by George Clooney, a top divorce attorney famed for creating the "Massey Prenup," a flawless prenuptial agreement. Taking on Bonnie as a client, Miles succeeds magnificently in court, leaving Donovan with absolutely nothing.
Meanwhile, Rex Rexroth (Edward Herrmann) is caught in a compromising situation during a role-playing session with a blonde in a motel room. This moment is interrupted by private investigator Gus Petch (Cedric The Entertainer), who records the scandalous encounter. Gus later delivers the video to Rex’s gold-digging wife, Marylin Rexroth (played by Catherine Zeta-Jones), who had married Rex with plans to gain financial independence through divorce. She hires Miles to represent her.
Marylin soon learns from her friend, serial divorcee Sarah Sorkin (Julia Duffy), that Miles is a formidable adversary, intensifying her interest in him. After failing to reach a settlement with him in negotiations brokered by her lawyer, Freddy Bender (Richard Jenkins), she accepts Miles's invitation to dinner where their repartee ignites a fierce rivalry. Miles, sensing an opportunity, employs Gus to gather additional intelligence.
In a dramatic courtroom scene, a concierge named Heinz, the Baron Krauss Von Espy (Jonathan Hadary), testifies about Marylin’s earlier attempts to find a wealthy, gullible husband. Consequently, she ends up with nothing in the settlement. Following this downfall, a desperate Donovan, now homeless and clinging to his Emmy statuette, becomes involved with Marylin, who seeks revenge by marrying an oil tycoon named Howard D. Doyle, played by Billy Bob Thornton. Despite Marylin insisting that Howard sign the Massey Prenup, he flamboyantly destroys it during the wedding ceremony, showcasing his love.
As time goes by, Marylin successfully divorces Howard and acquires his fortune. Their paths cross again in Las Vegas, where Miles is a keynote speaker at a conference dedicated to divorce attorneys. They quickly bond over their mutual loneliness, culminating in an impulsive marriage. To assert that he isn’t motivated by her wealth, Miles insists on the Massey Prenup, but Marylin tears it up. At the conference, he announces his shift from divorce law to pro bono work in East Los Angeles, only to later uncover the shocking truth: Howard D. Doyle is merely an actor from one of Donovan's soap operas.
As the drama intensifies, Miles's boss, displeased with the fallout, directs him to a hit-man named Wheezy Joe (Irwin Keyes). However, when news breaks that Rex has died, leaving Marylin a fortune due to his unchanged will, Miles rushes to protect her. Yet, Marylin is far from endangered, as her loyal rottweilers have the hapless Wheezy Joe cornered. In a twist of fate, when Miles arrives to assist, Wheezy Joe mistakenly turns his inhaler into a weapon and accidentally harms himself.
In the aftermath, Miles and Marylin convene to negotiate their divorce terms. Miles, yearning for another chance, retroactively presents a Massey Prenup, but Marylin tears it apart once more, leading to a passionate kiss that reignites their connection. In a final twist, Marylin reveals her plan to pitch a television show idea to Donovan, turning Gus Petch into the host of "America's Funniest Divorce Videos."
