What Happens in Vegas is a 2008 comedy film from Twentieth Century Fox starring Cameron Diaz as Joy and Ashton Kutcher as Jack.

The story revolves around two people who discover they've gotten married following a night of debauchery, with one of them winning a huge jackpot after playing the other's quarter set in Sin City,Las Vegas . Unhappy pair try to undermine each other and get their hands on the money while falling in love along the way.

The film started in Manhattan, a highly-strung stockbroker Joy is dumped by her fiance, whilst laid-back carpenter Jack is fired from his job. Both go with a friend to Las Vegas, where they meet. While drunk, that's the time Joy and Jack got married, but they decide to divorce after returning home. Jack wins a huge jackpot after playing with Joy's quarter. A judge decides that they cannot divorce right away, they first have to try to stay together. The one who does not cooperate will not get any share of the money. The newlyweds devise ever-escalating schemes to undermine each other and get their hands on the money, only to find themselves falling in love.