The fourth season of "Grimm" premiered on NBC in the United States on Friday, Oct. 24, 2014, at 9 p.m. The season ran for 22 episodes, with the finale airing on May 15, 2015.
During its fourth season, new episodes of "Grimm" aired simultaneously in Canada on CTV. In the United Kingdom and Ireland, "Grimm" premiered on Watch on Jan. 28, 2015.
In February 2015, midway through the fourth season, NBC announced the renewal of "Grimm" for a fifth season, which began airing on Oct. 30, 2015 in the United States. NBC ordered 22 episodes of "Grimm" for its fifth season.