Early in the morning in 1979, the whole world is getting ready for work "9 To 5".

We meet Violet Newstead, a single mom up for a promotion at her company, Consolidated, and her son, Josh.

Doralee Rhodes, an ambitious country girl, also works at Consolidated. Her husband, Dwayne, is supportive of her career.

Judy Bernly, overdressed and in the process of a divorce, is preparing for her first day on the job.

In the Office Bullpen, secretaries Maria Delgado, Kathy, and Margaret watch Judy arrive. Violet introduces herself, and Judy hugs her, confessing that she’s had a hard time lately in her personal life. Violet advises her to concentrate on work. Violet deduces that Judy has no office experience, and Judy admits that she’s been a stay-at-home wife – until recently, when her husband left her. Violet decides to show Judy the ropes around the office "Around Here".

Judy meets Roz Keith, the boss’s administrative assistant, who is a strict rule follower. Violet explains to Judy that their boss is a difficult man and then remembers that he asked her to get his wife a present. Violet commandeers Judy’s scarf for the gift just as Doralee introduces herself. Though Doralee’s very friendly, Violet informs Judy that she isn’t well liked "Back To Work!".

Violet introduces Judy to Mr. Franklin Hart in his office, where he takes the scarf for his wife from Violet. They go back to work. Doralee enters to take dictation. Mr. Hart gives Doralee the scarf, insisting they should date each other, even though they’re both married and Doralee has rejected him time and time again. Unaware of her husband’s behavior, Missy Hart enters with cruise brochures, excited about the possibility of a vacation.

In the Xerox room, Judy has lost control of the machine. Though Mr. Hart criticizes her and cracks jokes to an uncomfortable Bob Enright, Violet steps in to help her, and Judy resolves to try "I Just Might". Judy’s ex-husband, Rick Bernly, delivers the final divorce papers.

Josh wants Violet to stand up to Mr. Hart, but Violet has her eyes on a promotion. Doralee laments to Dwayne that her coworkers don’t treat her kindly, and he encourages her to be herself.

The next day in the Office Bullpen, Maria receives the mail boy’s paycheck by mistake and discovers that he makes much more money than she does. Joe, the office accountant, asks Violet out on a date, but she’s hesitant. Roz sends a memo forbidding employees to discuss salary information, and Doralee laments that no one in the office will give her a chance "Backwoods Barbie". Violet is furious when Bob Enright is promoted in her stead.

Doralee discovers that Mr. Hart has been telling people that she is his girlfriend, and that’s why the office workers have been treating her coldly. Roz announces that Maria has shared salary information, and Mr. Hart fires her. Margaret, Kathy, Maria, and Judy vent about what they’d like to say to Mr. Hart "Hey Boss".

Violet and Judy apologize to Doralee. They’re all discussing Mr. Hart when he pops into the kitchen to ask Violet for coffee. She’s just returned from doing the office grocery shopping, is angry and distracted, and accidentally puts rat poison into Mr. Hart’s coffee instead of sweetener. The coffee doesn’t smell right, so Mr. Hart hands it to Roz, who dumps it out and makes him a fresh cup. Violet notices that the rat poison and the sweetener look almost identical, and she thinks she’s poisoned Mr. Hart. In a panic, she calls for Doralee and Judy, and they come up with a plan while Roz eavesdrops on their conversation. Roz heads off to report what she heard to Mr. Hart.

Violet, Doralee, and Judy sneak into Mr. Hart’s office after hours, and he confronts them, claiming that they tried to kill him and threatening to call the police.

Doralee ties him up with the phone cord. They take him back to his house and tell him exactly what they think of him "Shine Like The Sun".

The next day in Mr. Hart’s office, Violet, Doralee, and Judy search and discover that he’s been stealing money from the company. Doralee encourages Violet to take Mr. Hart’s position as CEO "One Of The Boys". Roz is shocked that she’s been assigned to the Lester Language Immersion Center "5 To 9", while Violet and the others keep improving office life and re-hire Maria "Change It".

Violet confesses everything to Joe, who offers to help her "Let Love Grow".

As Judy is locking up at Mr. Hart’s house, she’s confronted by Rick. He wants her to take him back, but she turns him down "Get Out And Stay Out".

Violet and the others finally find concrete evidence of Mr. Hart’s crimes just as he escapes and shows up at the office. During their standoff, Russell Tinsworthy, chairman of the board, arrives to congratulate the office on the 20 percent rise in productivity. Violet, Doralee, and Judy explain to Mr. Tinsworthy that they do all the work while he takes the credit, and they confess to the events of the last two weeks. Mr. Tinswothy gives Mr. Hart a promotion – to the office in Bolivia – while Violet gets Mr. Hart’s old job as CEO "Finale".