As the clocks ring and the workers wake up Violet, Doralee, and Judy prepare for work 9 to 5. The workers begin another mundane and hellish day at work under Franklin Hart Jr, president of Consolidated Industries. Judy and Violet meet for the first time and Judy reveals she does not have any work experience, but Violet states she will be proud to train her and gives her a few tips and pointers for surviving office life Around Here. Franklin Hart Jr, is a domineering and equally lecherous man, who lusts after his secretary, Doralee, and has no shame in making those feelings known, which discomfits Doralee Here For You. Judy is having major issues on her first day (such as being unable to work a Xerox machine) and feels there is something more inhibiting her. All three women, in separate settings, share mutual feelings, but all feel they can overcome it and make it all work out in the end I Just Might. A new day rises upon the begrudged workers of Consolidated and life resumes as normal. Around the lunch hour, Doralee and Judy speak for the first time as Doralee asks Judy to go to lunch with her, but Judy subtly refuses and Doralee doesn't know why. She then reflects on her whole life, about just being a pretty face and nothing much more Backwoods Barbie. Violet is passed over for yet another promotion, which angers her since it is somebody that she personally trained. After a heated confrontation in Hart's office, Doralee finds out about Hart's rumor about their supposed 'affair', which infuriates her to the point of threatening him. All three of the women, who are now seemingly united in their contempt for Hart, go back to Violet's house and light up a joint. Suddenly, each woman lapses into a murderous fantasy involving Mr. Hart; Judy as an unforgiving femme fatale The Dance O' Death, Doralee as a crack rodeo star Cowgirl's Revenge, and Violet as a deranged Snow White Potion Notion. All of these sadistic fantasies soon culminate into a celebration of Hart's death, which is quickly nixed after Hart is discovered alive Joy To The Girls.
The next day at the office, Violet unwittingly acts out her fantasy and believes she put rat poison into Hart's coffee. They all go to the hospital in panic, but learn he was never there. Roz overheard the ladies in the bathroom and tells Hart, who concocts a plan to scare them by pretending he was actually poisoned and to threaten them with the police. After Hart leaves, Roz sings a song confessing her obsessive love and fantasies for him Heart To Hart. Hart confronts Doralee with the information and Doralee, acting on a fight or flight instinct, rips the phones out and ties up Hart with the wires, which he seems to get a quasi-sexual pleasure from. The women are seemingly puzzled as to what to do with Hart, but Judy and Violet create a plan in which they will imprison Hart in his own house. As they are carrying out their plan, they sing to Hart their issues with him and the problems in their own lives, but will begin to make the changes in their lives and have confidence to succeed Shine Like The Sun. The women, empowered, have restrained Hart to a mechanical harness above his bed.
After the Entr'acte, in Hart's office the three women are pondering on how they can keep the office in the dark about Hart's disappearance, when Doralee's skill of being able to forge Hart's signature comes into play. Judy and Doralee both point out to Violet that she is, in a sense, the new Operating Officer of the company. Violet then lapses in a fantasy and sings a song about she is now a hard-hitter like the rest of the male employees (who seems to rank above the women) One Of The Boys. Roz begins to get nosy and wonders where Hart actually is, which creates a new obstacle for the ladies to rid of. Judy formulates the idea to send Roz to a one month language seminar to learn French, which isn't necessary and is only a way to rid of her. Roz receives the memo from Violet and is heartbroken, because she believes that Hart doesn't like her, and that the time she isn't at work is lonely and boring 5 To 9. As Hart is still strung up in his bedroom, he passes time by watching countless hours of soap operas. Doralee enters to give him a meal and Hart lashes out at her saying that he still has the control and will use it when he is free. Doralee brushes him off and leaves the room. Hart begins to recount how most of the men in history had "downfalls" by women and that he is no different, which angers him Always A Woman.
Back at the office, the new changes the women have made under Hart's name have seemed to ease the workers' lives and changed their outlook on work Change It. Joe, who has shown admiration toward Violet through the show, asking her out many times, confronts her and asks why she rebuffs him. She claims she was a "one-man woman" and that her husband's death three years before has prevented her from dating again. Joe tells her that it is time to move on and possibly give someone new a chance Let Love Grow. Violet accepts, as they walk out of the scene holding hands. Later on that evening, Judy's ex-husband, Dick, shows up at Hart's house and asks her to take him back (since his secretary girlfriend dumped him). She rebuffs him and states she is a changed woman who will not crawl back to someone who broke her heart, showing strength as she orders him to leave Get Out And Stay Out.
The next day, Hart storms in to the office with Judy hostage, which shocks the women, who have collected evidence about Hart's "creative accounting" and embezzling practices to use against him. The women, seemingly defeated, prepare to submit to Hart's wishes when they learn that the CEO of Consolidated, Mr. Tinsworthy, is paying a visit. The women and Hart meet Tinsworthy, who, after noting the changes in office life, gives the credit to Hart. Violet and the others step up and say they made the changes, but are shot down. However, in a comedic twist, Tinsworthy sends Hart to manage the South American branch in Bolivia. Violet is then promoted to Hart's position as President of the company and a celebration ensues, while Roz is devastated over the loss of her obsession. The characters deliver epilogues about what happened after the events of the story (Finale: "9 To 5" Reprise). Hart was captured by natives in the jungles of Bolivia and was never seen or heard from again. Roz found a new love - Hart's wife. Violet and Joe have been together for the past 30 years and are very happy together. Doralee went to Nashville and became a successful country western singer. Judy is single and loving it and wrote a bestselling book, "Life Without Dick."