It's not Deion Sanders, Tyreek Hill or Bo Jackson ... no, the fastest NFL player ever is Chris Johnson -- so says CJ2K himself.
The legendary Tennessee Titans running back made the claim to TMZ Sports ... saying if he lined up for a race against every fast NFL legend ever -- and everyone was still in their prime -- he would've dusted them all.
"No question," Johnson says.
The statement is a bold one -- after all, Sanders alone is rumored to have once run a 4.