Kim Kardashian, Justin Bieber, Suni Lee Attend IShowSpeed's Series Launch Party

Kim Kardashian, Justin Bieber and Suni Lee all hit an event on Tuesday ... but no, it wasn't for an awards show -- it was all thanks to IShowSpeed!!

The streaming superstar hosted a night at the Los Angeles Memorial Coliseum ... and a bunch of A-listers were present for the premiere of his six-episode YouTube series, "Speed Goes Pro."

Some of the biggest celebrities rolled through in support ... including Kim K, who chatted with Speed about his 35-day tour that wrapped up in L.A. She also brought some of her kids to meet him ... earning her some major cool mom points.

JB also pulled up rockin' furry shades and a hoodie ... and jammed out to DJ TJ Mizell's tunes -- even when his own track, "Speed Demon," came on.

Speed was shocked to see Olympic medalist Suni Lee, who looked stunning in a red dress ... but was super shy for his stream.

The guest list didn't stop there ... WWE Superstars Sheamus, Drew McIntyre and Randy Orton were also there -- with Speed attempting to RKO the latter.

Remember, Orton did his signature move to Speed at WrestleMania 40.

FYI, "Speed Goes Pro" is a series where the athletic streamer goes head-to-head with some of the biggest sports stars ... starting with Tom Brady in episode one.

He also trained with New York Jets star Sauce Gardner and Brady's former teammate, Danny Amendola, in the vid ... all in an attempt to intercept the seven-time Super Bowl champ.