"There were never any plans for her to attend," says the rep.
Bullock, who has remained out of the public eye since the scandal broke over husband Jesse James's alleged infidelities, is nominated as Favorite Movie Actress for her work in The Blind Side and The Proposal. She's vying with Miley Cyrus, Megan Fox and Zoe Saldana.
Her rep had no comment on Bullock's whereabouts.
After learning of the explosive allegations against her husband, Bullock, citing "unforeseen personal reasons," pulled out of The Blind Side's London and Berlin premieres, which were subsequently cancelled by Warner Bros.
Last year, Bullock, 45, teamed up with Hugh Jackman at the 'tween-heavy Kids' Choice Awards, and was all smiles – even as she and the X-Men star were drenched with gallons of the event's signature green slime.
The show is one of the most-watched events of the year in children's TV, able to draw Hollywood A-listers because its young teen audience is the coveted movie-going crowd. This year, the 23rd annual, First Lady Michelle Obama will make a guest appearance.