In 1979, Ron Burgundy and Veronica Corningstone are married and are both co-anchors for a prestigious news network in New York City. One day, Mack Tannen, the most famous nightly news anchor in New York, reveals that he is retiring. He intends to promote Corningstone, making her the first female nightly news anchor in the history of television, and to fire Burgundy due to his continuously sloppy performance on air. Burgundy grows jealous of Corningstone’s success and storms out of the house, leaving her and their 6-year-old son Walter.
Six months later, Burgundy is back in San Diego, but barely able to hold a job due to depression. After being fired from SeaWorld and botching a suicide attempt, Burgundy accepts a job offered to him by Freddie Shapp with GNN, the world’s first 24-hour news network, for the station’s official launch. Along with his dog Baxter, he reassembles Champ Kind, Brian Fantana, and Brick Tamland. They are assigned the unpopular late-night timeslot while obnoxious rival anchorman Jack Lime is put in a primetime slot. Meanwhile, Burgundy finds that Corningstone has started dating psychologist Gary.
As GNN launches, Burgundy decides to broadcast what the people want to hear, rather than what they need to hear. He and his team devise a sensationalist and patriotic newscast. Their new approach proves to be a hit, beating Lime in ratings by a massive margin, and the other news networks scramble to emulate them. Ron also wins a bet with Lime forcing him to legally change his name to Jack Lame. Burgundy and his team are promoted to primetime, where they enjoy fame and fortune. Burgundy’s success excites GNN’s manager, Linda Jackson, and they begin a romantic relationship. Tamland meets a similarly eccentric GNN office worker named Chani and immediately falls in love. Burgundy lets his newfound fame get to his head and neglects his parental obligations to Walter, angering Corningstone. He also alienates Fantana, Kind, and Tamland, claiming he is tired of carrying them.
During a party celebrating GNN’s success, Lame causes Burgundy to slip and suffer a head injury, resulting in him becoming temporarily blind. Unable to read the news, Burgundy isolates himself in a lighthouse, unable to adjust to his temporary loss of vision. Corningstone arrives with Walter for a visit, announcing that she has quit her own job, and Burgundy bonds with his family, gradually adjusting to his disability. Burgundy and his son rehabilitate a small shark, naming him Doby before setting him free. Later, Burgundy discovers that Corningstone was concealing messages from his eye doctor regarding an experimental procedure, since she thought his blindness has been significant in the family bonding. He leaves angrily, gets his vision restored, and returns to GNN.
Back in New York, Burgundy is once again approached by Corningstone, who pleads with him to attend Walter’s piano recital. At the same time, an exclusive news story comes in, requiring Burgundy to cover it. However, on live television, Burgundy instead admits that news is supposed to inform, not entertain, and takes responsibility for the mistakes he made, following it up by quitting and walking off. He leaves for Walter’s recital but is intercepted by an angered Lame and his team and several other news teams, all of whom want to kill him due to his fame. Kind, Fantana, and Tamland arrive to defend him and a massive battle ensues. Burgundy gets attacked by BBC news team, then Gary rescues him with his mind powers. He tells Burgundy to get to the recital and the group makes a run for it to avoid the news, Burgundy’s old arch-rival Wes Mantooth arrives in time to save Burgundy from Lame’s news crew, before Tamland accidentally sets off an explosion. Burgundy manages to reach Walter’s recital in time, and reconcile with Corningstone. Burgundy, Kind, and Fantana later attend Tamland’s and Chani’s wedding on the beach. During the wedding, Ron spots Doby in the water and tries to greet him, only to be attacked, forcing Baxter to rescue him.