Elvis Presley once lived like royalty in Beverly Hills -- ya know, 'cause he was THE King -- and now you can too ... if you've got $20k to blow on an epic sleepover.

Axar.az reports citing TMZ, Elvis' former Bev Hills estate is now for rent at $4,000 a night -- but there's a catch ... you gotta stay for at least 5 nights. If you're 'bout that hound dog life, you're in for a real treat.

The 4-bed, 6-bath crib, which sits on a cliff, features floor-to-ceiling windows and glass walls in every room, plus a huge pool and spa. There's also a guest house out back, and it's still got the OG gates where Elvis used to greet fans in the '60s.

Check out the crib for yourself, bet you can't help falling in love with it.