The nominations for the Billboard Music Awards are out and leading the pack ... Adele, Rihanna and Lady Gaga!

Adele has been nominated in 18 categories including Top Female Artist, Top Billboard 200 Artist and Top Artist. Her single "Rolling in the Deep" is up for awards in seven categories.

Rihanna has been nominated for 13 while Lady Gaga earned 10 noms. Also up for some awards: Lil' Wayne in 10 categories and Party Rock peeps LMFAO in 17 categories.

Other artists nominated include Katy Perry, Justin Bieber, Bruno Mars, Nicki MInaj and Chris Brown ... just to name a few.

The Billboard Music Awards will take place in Vegas on May 20.

Click thru to see the complete list of nominations.