Doug Marrone wasn't lying ... the Jaguars head coach WAS arrested back in 1997 for the same thing Leonard Fournette got busted for last week!!
TMZ Sports has obtained police docs from June 20, 1997 ... when Marrone -- a Georgia Tech assistant at the time -- was popped for doing 57 MPH in a 35 in Daytona Beach Shores, Florida.
According to the docs ... Marrone was pulled over at 11:59 AM in a 1997 Buick with fellow GT assistant coach Lance Thompson riding shotgun.
Cops say when they checked Doug's record .