Bernard Rollen Williams III is an American male former track and field sprinter and winner of a gold medal in 4 × 100-meter relay at the 2000 Summer Olympics. He was the 200-meter dash silver medalist at the 2004 Summer Olympics and the 100-meter dash silver medalist at the 2001 World Championships in Athletics. He also won relay gold at the 2003 World Championships in Athletics and was the 100 m gold medalist at the 1999 Pan American Games.

The 4 × 100 metres relay or sprint relay is an athletics track event run in lanes over one lap of the track with four runners completing 100 metres each. The first runners must begin in the same stagger as for the individual 400 m race. Each runner carries a relay baton. Before 2018, the baton had to be passed within a 20 m changeover box, preceded by a 10-metre acceleration zone. With a rule change effective November 1, 2017, that zone was modified to include the acceleration zone as part of the passing zone, making the entire zone 30 metres in length. The outgoing runner cannot touch the baton until it has entered the zone, and the incoming runner cannot touch it after it has left the zone. The zone is usually marked in yellow, frequently using lines, triangles or chevrons. While the rule book specifies the exact positioning of the marks, the colours and style are only "recommended". While most legacy tracks will still have the older markings, the rule change still uses existing marks. Not all governing body jurisdictions have adopted the rule change.