Plot

Robbie (Adam Sandler) dreamed of one day becoming a big rock-star. But instead, he has become one of the most entertaining wedding singers in the town of Ridgefield, New Jersey in 1985. Robbie's band includes George Stitzer (Alexis Arquette) keyboardist and singer, Randy Razz (Teddy Castellucci) and John Vana (Teddy Castellucci).

At Robbie's latest wedding gig, he saves the wedding toast from being ruined by the groom's alcoholic brother David Veltri (Steve Buscemi) and catches the eye of a waitress at the function, named Julia (Drew Barrymore).

Afterwards, they both tell how they are engaged: Robbie to his girlfriend Linda (Angela Featherstone), and Julia to her boyfriend, Glenn (Matthew Glave). Noting Robbie's handling of the situation inside the wedding, Julia wants him to sing at her wedding, to which Robbie happily agrees to. Linda's fiance, businessman and bond investor Glenn Gulia, has yet to set a date. They have been engaged for 2 years and now Linda is starting to doubt Glenn's intentions. She even moved to Ridgefield so she could be closer to him. Angie (Christina Pickles) is Julia's mother and asks her to fake a pregnancy to pressure Glenn into marrying her quickly.

Eventually, Robbie and Linda's wedding day arrives, and everyone is there, except for Linda. It soon becomes apparent that Linda has decided not to go through with the wedding, leaving Robbie heartbroken and despondent. After the wedding is called off, Linda meets with Robbie and reveals that she fell in love with him for his ambitions of being a rock star with his band called "Final Warning", which was 6 years ago. She reveals her concerns of ending up being stuck in Richfield, married to Robbie, and raising kids in his sister Kate's (Jodi Thelen) basement. Kate is married to Andy (Frank Sivero) and has 2 kids Tyler (Patrick McTavish) and Petey (Gemini Barnett).

Robbie sinks into depression, causing his friends and family to be concerned. Robbie's brother Sammy (Allen Covert) attempts to get him to snap out of his misery and play another wedding gig. However, Robbie's sour mood disrupts the wedding toast, in which he insults the bride's father, and breaks into a dour rendition of the song, "Love Stinks." Julia meets with Robbie afterwards, hoping that he'll still play for her and Glenn's wedding. However, he now expresses doubt about participating.

Eventually, Robbie's spirits start to perk up, and he ends up doing a Bat Mitzvah with Julia acting as a waitress. After the festivities, Julia asks Robbie if he'll help her plan her wedding. Robbie agrees, and along with his brother Sammy, and Julia's cousin Holly (Christine Taylor). They do everything from trying wedding cakes, to hiring a limo driver (of which Sammy is the only one in town).

Robbie eventually goes out for a party with Holly, Julia, and Julia's fiance, Glenn. At the party, Robbie gets to see that Glenn is anything but a nice guy, as he notices Glenn has no problems ogling other women on the dance floor. Robbie learns from Glenn that he cheats on Julia frequently and plans to continue after they are married.

After everyone leaves, Holly tries to hook up with Robbie, but soon sees that he likes Julia. Julia and Robbie are increasingly confused by their deepening feelings for each other. When Holly tells Robbie that Julia is marrying Glenn for his money, he unsuccessfully pursues a job at a bank. Julia is dismayed at his materialism, and when he accuses her of the same, she becomes angry with him. Depressed, he decides to follow Sammy's example of only having shallow relationships with women, in response to which Sammy confides that he is unhappy and encourages Robbie to tell Julia how he feels.

Robbie grapples with his feelings, and eventually decides to tell Julia his true feelings. Meanwhile, Julia confides in her mother that she has fallen out of love with Glenn and has developed feelings for Robbie, and bursts into tears thinking about becoming "Mrs. Julia Gulia". However, upon arriving at her place, Robbie sees her in a window, in her wedding dress, speaking into a mirror (unheard to Robbie, she is saying his name, practicing saying she's 'Mrs Robbie Hart').

Heartbroken, Robbie leaves to get drunk and finds Glenn in the midst of his Pre-wedding bachelor party, arm in arm with another woman. After a heated exchange, Glenn punches Robbie and mocks him. Robbie stumbles home to find Linda waiting for him wanting to reconcile and passes out.

The following morning, Linda answers the door and introduces herself as his fiance to a crestfallen Julia. She runs to Glenn, who is sleeping off the events of the previous night and tells him she wants to be married immediately. He offers to take her to Las Vegas reluctantly.

Robbie awakens and, after shaking off his hangover from the previous night, rejects Linda's reconciliation, having realized how shallow she is during his time with Julia, and kicks her out. At the 50th wedding anniversary party of his neighbor Rosie, to whom he has been giving singing lessons, he realizes he wants to grow old with Julia and, with Rosie's encouragement, he decides to pursue her. Just then, Holly arrives and informs him of Julia's encounter with Linda, so Robbie rushes to the airport and gets a first-class ticket to Las Vegas.

After telling his story to his empathetic fellow passengers, which include Billy Idol, Robbie learns that Glenn and Julia are on the same flight. With the help of Billy and the flight crew, over the loudspeaker, he sings a song he has written called "Grow Old with You", dedicated to Julia. As Robbie enters the main cabin singing, Glenn tries to assault him only to be thwarted and shoved into a lavatory by the flight attendants with assistance from Billy and a large fan.

Robbie and Julia admit their love for each other and share a kiss. Billy, impressed by Robbie's song, offers to tell his record company executives about him. Later, Robbie and Julia are married, and a band led by Robbie's friend David performs at their wedding.