The deal includes $40 million in total guaranteed money. Kittle will also earn an $18-million signing bonus.
Kittle's new deal easily makes him the highest-paid tight end in NFL history with an average annual salary of $15 million. Austin Hooper will earn $10.5 million a year on his new deal with the Cleveland Browns, while Los Angeles Chargers tight end Hunter Henry is set to make $10.6 million under the tag this season.
Kittle, 26, has amassed at least 80 catches, 1,000 receiving yards, and five touchdowns in each of the last two seasons. The two-time Pro Bowler set the record for most receiving yards by a tight end in a single season when he amassed 1,377 in 2018.
San Francisco selected the Iowa product in the fifth round of the 2017 NFL Draft.
Kittle's extension marks the latest significant move in a busy offseason for the 49ers: