Garrett was reinstated from his suspension on February 12, 2020. On April 27, 2020, the Browns exercised the fifth-year option on Garrett's contract. He signed a five-year, $125 million contract extension with the team on July 15, 2020. In Week 2 against the Cincinnati Bengals, Garrett recorded a strip sack on rookie quarterback Joe Burrow which was recovered by the Browns during the 35–30 win. In Week 3 against the Washington Football Team, Garrett sacked Dwayne Haskins twice, including a strip sack that was recovered by himself during the 34–20 win. In a Week 4 game against the Dallas Cowboys, Garrett sacked Dak Prescott twice, one of which was a strip sack that resulted in a turnover, during the 49–38 win. His performance earned him AFC Defensive Player of the Week. In Week 7 against the Cincinnati Bengals, Garrett sacked Joe Burrow two more times and forced a fumble that was recovered by the Browns during the 37–34 win. As the month closed, Garrett won AFC Defensive Player of the Month for October after compiling six sacks, 14 tackles, four for a loss, and two forced fumbles.