The fourth production season of is widely regarded by fans and critics as the pinnacle of the show's original run on Fox. Airing from February 10, 2002, to August 10, 2003 , it consists of 18 episodes that balance high-concept science fiction with deeply emotional character development. Series Overview & Production Context
The complete set is available in the Futurama: Volume Four DVD/VHS box set . Key Story Arcs & Character Development
In "Leela's Homeworld," it is revealed that Leela is not an alien but a mutant whose parents gave her up to the Surface World orphanage to provide her with a better life.
Season 4 features some of the highest-rated and most influential episodes in the entire series. Futurama Season 4 Ratings - IMDb
Season 4 was initially intended to be the series finale following Fox's decision to cancel the show due to low confidence and erratic scheduling. Consequently, the season contains several "landmark" episodes that resolve long-standing mysteries, such as Leela’s true origin and Fry's destiny as "the chosen one".
The episode "The Why of Fry" explains that Fry’s cryonic freezing was not an accident but a plan orchestrated by the Nibblonians to ensure he would be in the future to save the universe.