Ballin'! Soulja Boy Buys $55 Million Jet

Soulja Boy turned his swag on for sure!

The 21-year-old rapper went all out for his 21st birthday, spending $55 million in total on a new private jet which he bought and spruced up.

The jet cost $35 mil ... but that's just the beginning. We're told the birthday boy is dropping an additional $20 million to pimp out his ride with all sorts of cool stuff ... like 12 custom Italian leather seats, flat screen TVs, 4 liquor bars, a special travertine tiled floor, and Brazilian hardwood cabinets.

We're told S.B. is also gutting the in-flight lavatory -- and replacing it with a giant, LUXURIOUS bathroom. Oh, he's also giving the jet a custom paint job ... to include his logo.

In addition, he is expected to drop another $300,000 on a birthday bash in Miami with appearances by the likes of Dwight Howard, Bow Wow and Sean Kingston.

Looks like the birthday boy's got some money to blow!

SOURCE: TMZ