The film opens in the early 2000’s in a retirement home. Sitting alone in a wheelchair is Frank Sheeran (Robert De Niro). He reflects on his life leading up to where he is now, starting with his profession as a “house painter” – in other words, a hitman.
In the 1950’s, Frank, a World War II veteran, lives in Pennsylvania working as a truck driver for a meat-packing company. He’s married to Mary (Aleksa Palladino) and has a daughter, Peggy (Lucy Gallina). In his work, he meets Russell Bufalino (Joe Pesci), who advises him to get his truck fixed. When Frank asks Russell his name, he instead changes the subject before bidding Frank farewell.
Frank starts to rub elbows with local gangster Felix “Skinny Razor” DiTullio (Bobby Cannavale), providing him with some of the goods he carries. On a delivery, a client sees that Frank’s truck is empty, and his employers accuse him of stealing. Frank goes to lawyer Bill Bufalino (Ray Romano), who helps Frank avoid legal repercussions by telling him to not give up the names of anybody that he was selling to. Later on, Bill formally introduces Frank to Russell, who is his cousin. Frank and Russell eat together, in which Frank discusses his time in the war, and how he was skilled at taking out enemy soldiers.
Frank is asked by a gangster called Whispers (Paul Herman) to take out Russell and his buddy Angelo Bruno (Harvey Keitel). Frank doesn’t go through with it and instead brings this information to Russell and Angelo, and when Frank offers to return the money to Whispers, Angelo assures Frank that he won’t be needing it anymore.
One afternoon, Frank goes home to see that Peggy is looking upset. Mary tells him that she knocked something over at the supermarket, and the store owner shoved her. Frank takes Peggy back to the store where he violently confronts the store owner, beating him and throwing him through the glass door before assaulting him in the street, in full view of Peggy and others walking by. This leads Peggy to become terrified of her father.
Russell brings Frank in on his crime business as a hitman, and he becomes well acquainted with a number of other gangsters (the onscreen text letting us know how all of them died horribly). During this time, Frank leaves Mary for a woman named Irene (Stephanie Kurtzuba), and they later have two other daughters, Connie and Dolores. He is eventually contacted by union leader Jimmy Hoffa (Al Pacino) after hearing about his work “painting houses”. Present Day Frank informs us that there is more to Jimmy that people don’t know other than his famed disappearance. Jimmy leads the International Brotherhood of Teamsters, and is also in league with Russell and his gang. Jimmy also has an issue with Teamsters Vice President Anthony “Tony Pro” Provezano (Stephen Graham), as he has his own plans for his business. Frank becomes a bodyguard for Jimmy, and he also brings him along to meet the family. Peggy is most fond of Jimmy, even more so than she is of Russell, whom she knows is bad news.
Jimmy and his Teamsters are staunchly against the Kennedys, which makes JFK’s election in 1960 hit a serious nerve for Jimmy. He rants to his men, and with Frank in the room, he thinks he is yelling at him too, but Jimmy assures Frank that he is not including him in the rant. After JFK is assassinated, Jimmy makes an insensitive comment to the press that Bobby Kennedy (Jack Huston), the former General Attorney, is now “just another lawyer.” Bobby later forms a squad to go after Jimmy, and he is eventually arrested for jury tampering. In Jimmy’s absence, the Teamsters is taken over by Frank “Fitz” Fitzsimmons (Gary Basaraba), who starts to use the group’s funds for himself or to make loans to the mob.
In prison, Jimmy finds that Tony Pro is also there for extortion. Tony makes some attempt to hash out his issues with Jimmy, but they can’t reach an agreement, and it just leads to them getting into a brawl, which is broken up by guards and other inmates.
During a parade, a random mobster is shot dead in the middle of a crowd. Frank and Russell figure that the gunman was sent by Crazy Joe Gallo (Sebastian Maniscalco), who works with black gangsters to carry out his dirty work. As the name suggests, Joe is a hotheaded loose cannon. On his birthday, Frank and Russell accompany Joe to see Don Rickles (Jim Norton) perform, in which Joe almost snaps at Rickles for a joke. The mobsters agree that Joe is too much of a liability, so Frank is sent to take him out. Present Day Frank recalls picking specific guns to do the job. He catches Joe having dinner with his family at Umberto’s, whereupon he shoots at Joe before following him outside and finishing him off in the streets, then making a getaway.
Jimmy is released from prison after Richard Nixon gives him a presidential pardon, but he can’t go back to the Teamsters. Regardless, Jimmy makes an effort to rise back to power, which involves dumping on other Teamster leaders and disregarding crime family activities. Russell asks Frank to talk to Jimmy about his behavior, but Jimmy assures Frank that he can’t be harmed, or else anyone involved will go to jail.
We then jump to 1975 where Frank, Russell, Irene, and Russell’s wife Carrie (Kathrine Narducci) are headed to a wedding for Bill’s daughter (the film had been cutting back and forth between this since the beginning). Russell tells Frank that it’s time for Jimmy to be taken care of. Frank arrives in Detroit after Jimmy is set to meet with Tony Pro and Anthony Giacalone (Patrick Gallo). Jimmy is surprised to see Frank with his foster son Chuckie O’Brien (Jesse Plemons) and fellow gangster Sally Bugs (Louis Cancelmi) after thinking Tony Pro stood him up. He is told that the meeting has been moved to another house where Tony and Russell are waiting for him. Frank takes Jimmy to the house, where Jimmy finds that it’s empty. Growing nervous and suspicious, Jimmy starts to walk out, only for Frank to shoot him twice in the back of the head. Frank leaves Jimmy’s body there, and it is later picked up by two other men who cremate his body.
Jimmy’s disappearance becomes nationwide news. The Sheeran family watches at home, and after Frank offhandedly mentions he hasn’t called Jo (Jimmy’s wife) yet, Peggy (now played by Anna Paquin), realizes her father had something to do with whatever happened to Jimmy. Present Day Frank informs us that this is the day that Peggy stopped speaking to him.
Frank, Russell, Tony Pro, and others are arrested for suspicions of Jimmy’s disappearance, while guys like Sally Bugs are murdered. Tony Pro dies, while Frank spends one last moment with Russell in prison before Russell is wheeled away to the hospital, where he later dies.
Frank is later released from prison and is sent to the retirement home. He has been diagnosed with cancer and he can barely walk. He visits Peggy at her bank job, but she walks away the moment she sees Frank, even as he begs her to talk to him. His attempts to reconcile with his other daughters is also unsuccessful. With this, Frank simply prepares for his death. He picks out a green coffin and the spot where he wants to be buried.
At the end of the night, Frank is taken to his room by an orderly. He asks the orderly to leave the door open, holding out hope that maybe someone in his family will still care to visit him.
