The Playboy tycoon posted a message on Twitter this weekend saying he'd given a ring to his girlfriend and playmate Crystal Harris.
Harris graduated from La Jolla High School and attended San Diego State University, according to the bio on her website.
At first, there seemed to be some kind of confusion about the type of ring Hef gave Harris. Later, to clear up any confusion he tweeted "Yes, the ring I gave crystal is an engagement ring."
This would be the third marriage for the 84-year-old playboy founder.
Hefner and Harris met in 2008 on Halloween night, the website said.