Filmed as a mockumentary, The Office follows the employees working at the Scranton office of Dunder Mifflin, as they go throughout their day. In the first season, Dundler Mifflin sends a sensitity trainer after manager Michael Scott (Steve Carell) makes off-color jokes. Also, Michael lets his Assistant to the Manager Dwight Schrute (Rainn Wilson) chose the health care plan, to the outrage of the other employees and Head Office informs Michael that they might be downsizing.
The second season has Michael giving out Dundees, the awards he came up with, which often insult the employees. On Halloween, Michael's boss Jan (Melora Hardin) tells him he has to fire someone by the end of day due to downsizing, and Michael agonizes over who it should be. The staff go on a mandatory "Booze Cruise," Michael injures himself on a George Foreman grill and on his birthday, Michael takes his employees ice skating.
In season three, after declaring his love for Pam (Jenna Fischer), who turns him down because she's engaged to Roy, Jim (John Krasinski) takes a job as Assistant Regional Manager at the Stamford branch of Dunder Mifflin. Pam decides not to go through with the wedding, but doesn't tell Jim how she feels about him. When downsizing leads to Stamford closing and some of the employees being transferred to Scranton, Pam learns Jim has begun to date Stamford transfer Karen (Rashida Jones).
Season 4 begins with Jim and Pam secretly dating, after he turns down a job at Head Office in New York. The job he interviewed for is given to former Scranton temp Ryan (B.J. Novak), who becomes self important. Another Stamford transfer, Andy Bernard (Ed Helms), is so angry by one of Jim's pranks that he has to go for an anger management course.
Pam goes to New York for a three-month semester of art school in Season 5. When Toby leaves for Costa Rica, Scranton gets a new H.R. rep, Holly (Amy Ryan), whom Michael falls for. Michael leaves Dunder Mifflin to start his own paper company.
Back in his job as Regional Manager at Dunder Mifflin in Season 6, Michael, who doesn't want to lose Jim, agrees to having him as a co-manager when CFO David Wallace (Andy Buckley) suggest Jim be promoted. However, the two rarely agree on how the office should be run. Dunder Mifflin is bought out by Sabre, a printer company, but keeps all of the Scranton staff.
Holly has to move to Colorado to take care of her elderly parents in Season 7, so Michael decides to go with her. He trains a new boss, Deangelo (Will Ferrell).
In season eight, Andy (Ed Helms) is promoted to Regional Manager after Deangelo has an accident. Meanwhile, Jim (John Krasinski) and Pam are expecting a new baby, Erin is dealing with lingering feelings for Andy, and Angela (Angela Kinsey) becomes even more involved with a charming politician, whom Oscar (Oscar Nuñez) swears is gay.
In the final season, Jim has invested in a sports start-up, which means he's away a lot. Dwight and Angela's relationship progresses, and a new salesman has a crush on Erin. The documentary is finally made and aired on PBS, and the employees get together for the screening.