In 1994, we meet Sandy Wexler (Adam Sandler), an eccentric talent manager operating in Los Angeles. Sandy is notorious for his outrageous personality; he approaches aspiring stars on the streets, often boasting exaggerated stories to make himself seem more important. He's known for having a ridiculous laugh that’s over-the-top, along with a habit of eating with his mouth open. Living in a cabana by a lavish pool in Bel Air—courtesy of his landlord Firuz (Rob Schneider), who needs Sandy around for legal reasons—Sandy struggles to find success for his clients. They've had little luck, except for one former client, Alfred, who only found fame after leaving Sandy's management.
Sandy currently manages a quirky group of talents, including Ted Rafferty (Kevin James), a ventriloquist who Sandy believes in wholeheartedly; Kevin Conners (Colin Quinn), a comedian; Amy Baskin (Jackie Sandler), an actress; Gary Rogers (Nick Swardson), a daredevil known for a nasty accident involving a jump over trailers and an unfortunate encounter with an eagle; and finally, Bobby Barnes (Terry Crews), a wrestler.
During a visit to Six Flags, Sandy spots Courtney Clarke (Jennifer Hudson), a beautiful young woman with an astounding voice, performing on stage. Captivated by her talent, he quickly persuades her to let him manage her career, but only after gaining permission from her incarcerated father, Willy Clarke (Aaron Neville). Determined to transform Courtney into a star, Sandy undertakes a drastic makeover for her, which includes everything from makeup to dancing lessons, and even arranging for profile shots by a photographer named Yuri (Ido Mosseri).
Known for his kindness towards newcomers, Sandy’s interactions with them always leave a lasting impression. For instance, Barry Bubatzi (Milo Ventimiglia), who previously benefited from Sandy’s mentorship, now holds a prominent position at a recording studio. Meanwhile, Sandy’s neighbor Cindy Marvelle (Jane Seymour) flirts with him despite the terminal condition of her husband, Peter (Sandy Wernick).
After recording Courtney’s demo at a low-budget studio—where he struggles to get it done due to a stoned technician named Jared (Jared Sandler) who forgets to press "record" multiple times—Sandy finally secures a meeting at a studio, leading to her signing a deal. In celebration of this success, he invites all his clients over to his house, but the festivities quickly spiral out of control as they end up in Firuz's pool, igniting a warning from Firuz that this is his "strike one."
As Courtney begins to release a series of successful singles, Sandy's antics tour a rocky terrain. His gaffes include offending music producer Quincy Jones at a party and misguiding Courtney about appearances on shows, which leads to tension in their working relationship. Complicating matters further, Courtney's rapper boyfriend Bling (Lamorne Morris) convinces her that Sandy is inhibiting her rising stardom, leading Sandy to resign as her manager despite his desire for her to continue recording.
As Sandy grapples with his feelings for Courtney, she quickly rises to fame, culminating in her winning a Grammy. However, her newfound success sends her into a spiral of dissatisfaction, leading to struggles with alcohol and troubled relationships. In a moment of desire for connection, she seeks out Sandy, but a one-night stand offers no resolution, and she eventually announces her retirement from show business to marry.
Devastated by her decision, Sandy's chaos escalates; he concocts ludicrous schemes that drive away all his clients except for Ted. Ted’s big break comes when he auditions for a role after the lead's tragic demise, and the network pressures Sandy to finalize a deal. In a shocking turn of events, Sandy suffers a heart attack yet perseveres, attending the meeting to secure a lucrative contract for Ted.
During a chance encounter at Six Flags, Sandy meets Alfred, later revealed to be Weird Al Yankovic, where Sandy learns an important life lesson about honesty. Al encourages Sandy to come clean and embrace the truth, leading to a heartfelt confession to Courtney at the Griffith Observatory. Their feelings are reciprocated, and the two marry in a whimsical ceremony officiated by one of Ted’s puppets.
Emerging from this journey renewed and authentic, Sandy not only reclaims his former clients but also welcomes many new ones into the fold. Finally, he and Courtney discover the humorous reality that a puppet cannot officiate marriages, prompting them to tie the knot for real after a two-decade-long adventure.
