Former student Mike Ross makes a living illegally taking the Law School Admission Test for others. To pay for his grandmother's care, he agrees to deliver a case of marijuana for his best friend Trevor, a drug dealer. Mike astutely avoids being arrested in a sting, only to stumble into a job interview with Harvey Specter, called the best closer in the city. Mike's knowledge of the law impresses Harvey enough to win him the associate position, even though Mike didn't attend Harvard. Together they try cases for the firm while maintaining the secret that Mike is a fraud.

Jessica Pearson, the managing partner, learns Mike's secret, but other issues take precedence when co-founding partner Daniel Hardman returns to the firm, pressuring Jessica and Harvey. Mike begins to foster a relationship with paralegal Rachel Zane. Mike tells Rachel he's a fraud.

Darby's presence in the firm gives Harvey leverage to seek a position as a named partner. Meanwhile, the merger causes Louis Litt to clash with his British counterpart. Darby International client Ava Hessington draws Harvey into a lengthy trial against his former mentor. Mike leaves newly renamed Pearson Specter to take a position as an investment banker.

Mike's new job puts him and Harvey on opposite sides of a takeover battle, causing the SEC to accuse them of collusion. When Mike is fired, Louis goes to extreme lengths to persuade Mike to come back to Pearson Specter, rather than working for shady billionaire investor Charles Forstman. Mike proposes to Rachel; Donna leaves Harvey to work for Louis.

Harvey struggles with losing Donna and begins to open up to a therapist. Rachel's wedding plans and her relationship with her parents are both overshadowed by Mike's secret. Mike and Harvey both resign to protect their future, but Mike is abruptly arrested for fraud. Mike accepts a plea bargain, pleads guilty, and turns himself in so that no one else will go to jail. At the wedding, Mike tells Rachel that he will not marry her now. Harvey escorts him to prison making their last few goodbyes.

A two-year prison sentence puts Mike at the mercy of Frank Gallo, an inmate with a grudge against Harvey.  Rachel works an Innocence Project case for her law professor; Jessica chooses to leave her position to pursue her own life. He struggles with his fraud being public knowledge but obtains a job at a legal clinic. Harvey helps both Rachel and Mike pass the Bar, and persuades Mike to come back to the firm.

Donna takes a position as COO, and Harvey's friend Alex joins the team. Harvey begins dating his former therapist, Paula; Louis sees a therapist of his own, with mixed results. Rachel begins her career as an attorney, having passed the Bar. Mike continues to work pro bono cases at the clinic, with Harvey's blessing. Louis and Sheila reconnect; as does Jessica with her family in Chicago. Mike and Rachel accept a job offer in Seattle to run their own firm that takes on class-action suits, and get married before leaving. 

As Mike and Rachel leave after getting married, Robert Zane is now the managing partner of Zane Specter Litt, with Donna remaining in her COO role. Robert hires a new senior partner, his right hand and fixer Samantha Wheeler. Louis learns that Sheila is pregnant. Donna and Harvey finally admit their feelings for one another as Season 8 ends, but Donna's mishandling of client/boyfriend  forces Zane to sacrifice his legal career for the good of the firm.

Faye Richardson, a special master from the bar is sent to oversee the firm due to the perception of the underhanded tactics they have been involved with for years. At the end of the season, Louis marries Sheila and Sheila gives birth to their baby and Harvey marries Donna and they move with Mike and Rachel to Seattle. Louis names Katrina as name partner and remains to lead Litt Wheeler Williams Bennett firm.