What's the fastest 40-yard dash time?

The fastest 40 yard time recorded in the modern era (electronic timing) was by Maurice Greene at the 2001 track and field championships: 4.21 seconds. The fastest time recorded in the NFL was by Fabian Washington in the 2005 scouting combine: 4.25 seconds

Well done, GD Kimble. Do you have sources for those times?

2007-2008 NFL League Press Kit

Lucky.

40 yard dash times reported by the NFL aren’t comparable to track 40 yard dash times. On the track, time is measured electronically and runners are on a measured, level surface and respond to the gun. At the combine and pro days, timing is by hand, surfaces are uneven and inexpertly measured, and the clock starts when the timer sees the athlete start. This all adds up to NFL 40 yard dash times being about .5 seconds “faster” than they would be in a track event (although the shortest track event is the indoor 50 meters – about 54 yards)

3.9 by Joey Galloway

@ac4king, Do you have a source for that time? That’s unbelievably fast as you can run a 4.2 and be considered blazingly fast, even by NFL standards.

For the first person who answered your wrong because Darrell Green who played for the Washington Redskins ran the 40 yard dash in 4.24 seconds.