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.

Christine Arron is a former track and field sprinter, who competed internationally for France in the 60 metres, 100 metres, 200 metres and the 4 × 100 metres relay. She is one of the ten fastest female 100 metres sprinter of all time with 10.73 secs, which is still the European record. She set the record when winning at the 1998 European Championships, where she also won a gold medal in the 4 × 100 m relay. Also in the relay, she is a 2003 World Championship gold medallist and a 2004 Olympic bronze medallist.