Defensive coordinator Jerry Gray retained Winfield and Nate Clements the starting cornerback duo in 2003. On October 5, 2003, Winfield collected a season-high 12 combined tackles (11 solo) as the Bills defeated the Cincinnati Bengals 22–16. On November 23, 2003, Winfield recorded ten combined tackles (seven solo) and made his first career sack during a 17–14 loss against the Indianapolis Colts in Week 12. Winfield sacked Colts’ quarterback Peyton Manning for a six-yard loss during the first quarter. Winfield started in all 16 games in 2003 and recorded a career-high 107 combined tackles (92 solo), 11 pass deflections, two forced fumbles, one sack, and an interception.