R&B star Estelle leads the nominations after being listed five times - for best UK female, album and song, and in the R&B/soul and video categories.
X Factor winner Lewis is also up for three awards - best UK female, best video and best album for Spirit.
The ceremony will be hosted by Spice Girl Mel B and Run DMC founder Rev Run.
All categories have been decided as a result of votes from the public.
Other nominees include last year’s best male winner, Dizzee Rascal, who is nominated again for best male, as well as for best song and best hip-hop act.