During Week 4 of the 2015 season, Timmons had a season-high 11 tackles and sacked Ravens quarterback Joe Flacco for his first of the season during a 20–23 loss to the Baltimore Ravens. On October 18, 2015, he had six combined tackles and intercepted Carson Palmer in a 25–13 defeat over the Arizona Cardinals. On January 3, 2016, he recorded ten combined tackles and a season-high 1.5 sacks in a 28–12 win over the Cleveland Browns. Timmons finished the season with 119 combined tackles, 77 solo tackle, one interception, and a forced fumble.