Per ESPN's Adam Schefter, Dawkins agreed to a four-year deal worth $60 million that will keep him with the Bills through 2024.
Per NFL Network's Ian Rapoport, the extension includes $34 million in guaranteed money for Dawkins.
Dawkins has established himself as a key part of Buffalo's offensive line over the past three seasons. He has appeared in all 48 regular-season games, including 43 starts, since 2017.
Per Pro Football Focus, Dawkins finished last season with the highest pass-blocking grade of his career in 2019 (77.3) and played a career-high 1,099 snaps. He's also been a versatile weapon in goal-line situations, catching one touchdown pass in each of the past two years.
Dawkins was entering the final year of his rookie contract with a base salary of $985,441, per Over the Cap.
A second-round draft pick out of Temple in 2017, Dawkins made his first start at left tackle in Week 3 of his rookie season. He moved into the starting lineup full-time seven weeks later and has held down that role ever since.