Harvill, 28, had his wife and two young sons in the crowd for his 107-metre (351-foot) record attempt at the Moses Lake Airshow on Thursday morning.
The daredevil was running through a series of warmup jumps when he crashed at Grant County International Airport, ABC News reports.
Video of the crash shows his motorcycle falling just short of the landing target on a dirt hill. Harvill appeared to lose his helmet and pitch over the handlebars before crashing into the slope of the hill.
He was taken to hospital where he was later pronounced dead.
“We regret to report today at our first event of the airshow — the Guinness World Record Jump Attempt, Alex Harvill was injured during his warm-up before the jump and has been taken to the hospital,” the Moses Lake Airshow said in a statement on its Facebook page after the crash Thursday.
The Grant County Sheriff’s Office later confirmed that Harvill had died.
“Our deepest sympathies go out to Alex’s family, friends and loved ones,” the sheriff’s office said in a statement.
Harvill was a professional motorcross racer who held two previous motorcycle jump records. He grew up idolizing Evel Knievel and would often jump his bike in the sand dunes near the Grant County airport as a child.
Harvill’s wife, Jessica, said before the event that he spent two weeks preparing for the jump, although he had not used the ramp prior to Thursday’s run.
Jessica gave birth to the couple’s second child in May.
A GoFundMe campaign to cover her expenses has raised more than US$42,000 to date.