There is much debate on who holds the fastest 40 time. Now, the 40 yard dash or simply "The 40" began with NFL Scouts. Therefore, I will not mention any olympic sprinters in my answer. Moving on, supposedly, Willie Gault of the Bears back in the 80's ran less than 4.1. He was termed the Fastest Man in the NFL during his tenure. There are many others that have recorded less than 4.2 and that includes, Bo Jackson, Deion Sanders, Joey Galloway, and D'Angelo Hall (rubber track).
Deion Sanders has a recorded 40 yard dash time of 4.27 seconds. This places him among the fastest in the National Football League.
Green's fastest recorded 40 time is 4.09 seconds. ------------------------- Green's fastest unrecorded 40 time is 3.81 seconds.
4.28 maybe
4.39
4.38
The fastest 40 yard dash time is 4.22 seconds, achieved by John Ross at the NFL Scouting Combine in 2017.
Bo Jackson was 4.12
4.3
The NFL's fastest official 40 yard dash time was 4.25 seconds by cornerback Fabian Washington.
Vernon davis
4.40 was Chad Johnson's fastest time.
my brother goat sets the record for best 40 yard dash time and its 4'01
his fastest was a 4.29 and his slowest was a 4.60
4.2 sec
4.28
4.05 4.05
According to several online sources, Bob Hayes' time in the 40 yard dash wasn't recorded. See The Fastest 40 Yard Dash Ever.