Rock, who's been in the films "Head of State" and "Dogma," is best known for his standup comedy specials "Bigger & Blacker," "Bring the Pain" and "Never Scared."
Rock, 39, has previously hosted the MTV's Movie Awards.
"I am a huge fan of Chris Rock," said Gil Cates, the producer of the Oscars telecast. "He always makes me laugh and he always has something interesting to say. Chris represents the best of the new generation of comics. Having him host the Oscars is terrific."
The one-time "Saturday Night Live" regular has won three Emmys for his TV programs and two Grammys for his comedy albums.
Rock currently is shooting a remake of "The Longest Yard" with Adam Sandler (search) and recently provided the voice of the zebra in the animated feature "Madagascar," both to be released in May 2005. His other film credits include "Pootie Tang," "Bad Company," "Down to Earth" and "Nurse Betty."
The 77th Academy Awards telecast is set for Feb. 27.