Saturday Night Live welcomes two of Hollywood's hottest young stars and two of the biggest names in pop music for its April shows. On April 14, Emmy winner Shia LaBeouf makes his SNL debut. One of the most sought-after young actors working today, LaBeouf stars in the upcoming thriller Disturbia and the eagerly anticipated summer movie Transformers.

Returning to "SNL" for her third appearance is multi-platinum musical guest Avril Lavigne. The Grammy nominee and seven-time Juno Award-winner will perform songs from her eagerly awaited third album "The Best Damn Thing."

The following Saturday, April 21, finds screen siren Scarlett Johansson returning to Studio 8H. With more than a decade of work under her belt, the four-time Golden Globe nominee and BAFTA winner, Johansson has built a solid reputation as one of Hollywood's most talented young actresses.

Joining Johansson on the show is cutting edge musician Bjork. Hailing from Iceland, Bjork has established herself as one of the most innovative and unique figures in alternative music. This is her second appearance on 'SNL,' performing selections from her soon-to-be released sixth CD "Volta."