Kemp will effectively replace Ian Desmond, who announced Monday evening he's opting out of the 2020 season.
It remains to be seen how much playing time Kemp will get in Colorado's outfield or if he'll be part of the team's Opening Day roster as a potential option at DH. The Rockies currently feature David Dahl, Charlie Blackmon, Sam Hilliard, and Raimel Tapia as their primary outfielders.
Kemp, 35, entered spring camp with the Miami Marlins as a non-roster invitee but was not included on the team's 60-man player pool this week.
The three-time All-Star finished second in National League MVP voting in 2011 when he hit .324/.399/.586 with 39 home runs, 40 stolen bases, and 126 RBIs with the Los Angeles Dodgers.
Kemp returned to the Dodgers in 2018 after splitting four seasons between the San Diego Padres and Atlanta Braves. He earned a spot on the NL All-Star roster that year and finished the season with a .290 batting average and 21 homers in 146 games.
He was subsequently traded to the Cincinnati Reds alongside Yasiel Puig that offseason but lasted only 20 games before the team released him in early May.