The third season of the American science fiction television series Fringe commencing airing on the Fox network on September 23, 2010, and concluded on May 6, 2011. Twenty-two episodes long, the season was produced by Bad Robot Productions in association with Warner Bros. Television, and its showrunners were Jeff Pinkner and J.H. Wyman. Lead actors Anna Torv, John Noble, and Joshua Jackson reprised their roles as FBI agent Olivia Dunham and the father-son duo Walter and Peter Bishop. Previous series regulars Lance Reddick, Jasika Nicole, and Blair Brown also returned, along with recurring guest stars Kirk Acevedo, Seth Gabel, and Ryan McDonald.
Building off the finale from the previous season, Fringe's third season dealt with a war between the prime and parallel universes. During the first part of the season, odd-numbered episodes mostly took place in the parallel universe and have a red title sequence, while even-numbered episodes mostly took place in the prime universe and have the original blue title sequence. In episode eight, "Entrada", the title sequence is a mixture of blue and red, and since have been either blue or red or both to signify the universal focus of the episode. In the rest of the season, however, the episodes focus on the prime universe with brief shifts to the parallel universe.