The founder of Luminar Technologies -- a potential major player in self-driving cars -- is snatching the crown Kylie Jenner once wore ... now that he's the world's youngest self-made billionaire.

Austin Russell's only 25, but he's worth a whopping $2.4 BILLION after his company's stock market debut Thursday ... which saw its share price soar to $22.98, giving the company a market value of about $7.8 billion.

Russell owns about a third of that, so do the math ... and yeah, the dude's balling. Forbes dubbed him the world's youngest self-made billionaire, and his wealth is expected to climb even more Friday along with Luminar's stock price.

As you'll recall, Forbes had previously given Kylie that title in August 2018, but earlier this year -- after some forensic accounting -- determined she actually came up about $100 mil short.

Of course, Kylie's "self-made" status was also called into question, but that doesn't seem to be the case for Russell ... who dropped out of college in 2012 to start Luminar.

AR's company's pretty cool ... it makes a device called lidar scanners that use lasers to give autonomous cars a 3-D view of the road and surroundings. The company's already struck deals with Volvo, Daimler Truck and Intel’s autonomous vehicle unit ... and is projected to start raking in billions annually.

For now, though ... it's given a 25-year-old dropout serious bragging rights.

This story originally appeared on: TMZ - Author:TMZ Staff