The new deal is worth more than $21 million, and it can be worth up to $24 million with incentives, sources told NFL Network's Ian Rapoport.
Doyle was set to become a free agent after the 2019 season. He started 12 games this season, amassing a team-leading 36 catches for 377 yards and four touchdowns.
The 29-year-old went undrafted in 2013 and was claimed off waivers by the Colts after being cut by the Tennessee Titans. In seven seasons in Indianapolis, Doyle's posted 2,105 yards and 18 touchdowns on 236 receptions, including an 80-catch, Pro Bowl-level campaign in 2017.
The Colts placed tight end Eric Ebron on injured reserve with an ankle injury after Week 12. In their first game without Ebron, Doyle hauled in 6 of 11 targets for 73 yards and a score in Week 13.