On March 13, 2019, Beasley signed a four-year, $29 million contract with the Buffalo Bills. Beasley caught his first touchdown reception with the Bills in a 31–21 Week 6 win over the Miami Dolphins. Against the Dallas Cowboys, his former team, on Thanksgiving Day in Week 13, Beasley finished with 110 receiving yards and a touchdown as the Bills won 26–15. In Week 16 against the New England Patriots, Beasley caught seven passes for 108 yards during the 24–17 loss. Overall, Beasley finished the 2019 season with 67 receptions for 778 receiving yards and six receiving touchdowns.