Joe Mixon is mourning the nine people who died in a horrific plane crash in Florida ... revealing he flew on the same jet with the same two pilots just weeks before the deadly disaster.

The former NFL running back shared the chilling connection on social media Monday ... saying he was "absolutely devastated" by Sunday's crash and had flown aboard the same aircraft just last month.

"They were incredible professionals and genuinely wonderful people," Mixon wrote of the two pilots, who were among those killed.

Mixon also paid tribute to 20-year-old co-pilot Nathalia Gadelha ... he says learning about her life and promising future made the tragedy even more heartbreaking.

The Learjet 60 was traveling from Austin, Texas, to the Bahamas when it crashed in Palm Beach County Sunday afternoon, killing all seven passengers and both pilots. Among the victims were a couple from Texas and their two young children. They were traveling with their nanny and two friends and were flying to the Caribbean to celebrate a birthday.

Investigators are looking into the cause of the crash ... with reports of icing and turbulence before the plane went down.

Mixon ended his emotional message with a reminder to cherish those closest to you ... "Love on your loved ones while you can, because you never know what tomorrow may bring."