The Athletic first reported the agreement. The total value of the deal is $55 million and has a player option for a fifth year at $10 million, with a $5 million buyout, sources told ESPN's Buster Olney.
Los Angeles adds the best center fielder on the market to a team that was seeking a right-handed bat to complement its deep lineup.
Pollock, 31, hit .257/.316/.484 with 21 home runs, 65 RBIs and 13 stolen bases in 113 games for the Arizona Diamondbacks last season, but he missed nearly two months with a broken left thumb. It was the latest in a line of injuries that have prevented Pollock from playing more than 113 games in a season since his breakout All-Star turn in 2015. He passed his physical with the Dodgers.
Pollock's presence deepens a lineup that lost right-handed outfielders Yasiel Puig and Matt Kemp in a trade that landed the Dodgers a pair of prospects from the Cincinnati Reds. While Cody Bellinger can play center field, the addition of Pollock allows him to move to his natural position, first base, when necessary. Los Angeles' versatility is one of its hallmarks, and while it could have rotated Bellinger, Kike Hernandez and Chris Taylor in center, Pollock's lack of a distinct platoon split would allow the Dodgers to play him every day.
The signing puts the Dodgers on the edge of the $206 million competitive-balance tax threshold. Currently, only the Boston Red Sox are in excess of the luxury tax, and after dipping beneath it last season, the Dodgers would pay only a 20 percent tax on their payroll over the $206 million number.
Pollock was issued a $17.9 million qualifying offer by the Diamondbacks on Nov. 2, but he declined, instead opting for free agency. Since Pollock's deal is for more than $50 million, the Diamondbacks will receive a draft pick following the first round.
Pollock missed all but 12 games in 2016 after fracturing his elbow in a headfirst slide at home in the team's final exhibition game. In 2017, he missed nearly two months with a groin injury.
His best season came in 2015, when he hit .315 with 20 home runs, 39 doubles and 39 stolen bases in 157 games, earning his first All-Star appearance along the way. His 192 hits led all outfielders, and he won his first Gold Glove for his outstanding defense.
A first-round draft pick out of Notre Dame in 2009, Pollock is a career .281 hitter with 74 homers, 264 RBIs and 367 runs in 637 major league games.