When the character of Alec was conceived for the series' season 2, the writers knew they wanted him to be a somewhat amoral X5 with a sharp wit. They chose to immediately hire Jensen Ackles for the role, who had previously played a rogue serial killing X5 in a season 1 episode. They explained the actor's return in a different role by saying that Alec was his former, and deceased, character's twin. Although they had only seen Ackles as a dramatic actor in his previous roles, everyone in the production was pleased to see that Ackles had a natural talent as a comedian.
Season 1 begins and ends the same: "Sometimes it seems like it happened to someone else, like maybe it was a story I heard. Even though I know it happened." Max says it atop the Space Needle in the Pilot and Logan says it atop the Space Needle in the season finale.
Several scenes of the children training at Manticore were edited for the opening scenes of Hitman (2007), which has a similar theme of genetically enhanced children being trained as assassins and a protagonist (Agent 47) with a barcode on the back of his neck.
Co-producer Kenneth Biller said in a Season 2 DVD interview that their filming location, Vancouver, would not allow them to "trash" a nice neighborhood. Hence, Terminal City had to be built from scratch.
Max's Phone number, clearly heard near the beginning of the episode "Harbor Lights" when dialed by Logan, (He is forwarded to her pager) are the first few (9) notes of the theme song to "The Wheel of Fortune".
Although both shows are listed as only having 21 episodes, they each have 22 episodes when re-aired. The first season has 21, but the pilot is approximately eighty-five minutes (twice the length of other episodes). The second season (and series) finale, "Freak Nation," is an hour and a half, which splits the episode during re-airings.
A "Dark Angel" video game based on the series for PS2, XBOX and PC was published by Sierra Entertainment in May 2002. Jessica Alba and Michael Weatherly returned to provide the voices of Max and Logan.
Eliza Dushku, the original choice for Max, later went on to star in the short-lived science fiction action series Dollhouse (2009) as Echo, a secret agent whom is implanted with false memories and skills for various missions.
Jessica Alba later starred in the Marvel comic book film Fantastic Four (2005) as Susan Storm. In the film, Susan Storm becomes a super hero with the ability to turn invisible when her genes are altered by cosmic radiation.
The series takes place in a post apocalyptic future and the series main protagonist is called Max. An obvious nod to Mad Max (1979) and it's sequels. James Cameron had cited Mad Max 2: The Road Warrior (1981) as one of his influences behind The Terminator (1984).
James Cameron later appeared in 4 episodes of the TV series Entourage (2004) which he played himself and Jessica Alba later starred in it's feature film follow-up Entourage (2015) which she played herself.
Max followed a long line of strong female character in James Cameron's work, including Sarah Connor and Ellen Ripley and Dark Angel is considered to be part of a wave of shows in the late 90s and early 2000s that feature strong female characters, alongside Buffy the Vampire Slayer (1997), Xena: Warrior Princess (1995) and La Femme Nikita (1997).