- Actingfor Two: some X5s have clones, such as Ben's clone Alec (both are played by Jensen Ackles) and Max's clone Sam (both are played by Jessica Alba).
- Joshua had a younger brother named Isaac, who was also played by Kevin Durand.
- Geneva Locke played both Max's younger self in flashbacks and her X7 clone in the present.
- Creator Backlash: In the commentary for the season one finale, Jessica Alba praises the first season immensely and then completely brushes off season two like it was yesterday's garbage.
"The second season I'm not even going to mention because that really wasn't the show. The first season was definitely the show."
- Development Gag: When Max meets self-made "superhero" Phil in the episode "I and I Am a Camera", he asks her if her name stands for Maximum Girl. "Maximum Girl" was a working title for the show.
- Executive Meddling: Part of the reason for the sudden change in the show's thematic elements between the first and second season, supposedly an attempt to tone down the show's dystopian atmosphere in the wake of 9/11.
- Friday Night Death Slot: Shipped here in its second season. The show that replaced it in that particular timeslot? Firefly. Cue fan-war.
- Romance on the Set: Jessica Alba (Max) and Michael Weatherly (Logan). They were engaged.
- Similarly Named Works: There is a video game Dark Angel based on this series, which should not be confused as having anything to do with the video game Dark Angel: Vampire Apocalypse.
- There is also an adventure supplement for Shadowrun with the title Dark Angel, and though both the game and the show are set in near-future Seattle, the adventure was released about a decade before the TV show first aired.
- Star-Making Role: For Jessica Alba.
- What Could Have Been:
- The audition tapes on the season one DVD reveal that there were originally going to be only six escapees, rather than the final number of twelve, and that Jondy was to be the subject of "Cold Comfort" and not Brin.
- Biggs was originally going to be Krit, but Joshua Alba was unavailable at the time. There were also plans to have Syl take on what eventually became Cece's role and to bring back Lisa Ann Cabasa as Tinga's twin.
- Fan Nickname: "DARK FUCKING ANGEL", or DFA for short.
- The Pete Best: All of their drummers before Hoglan except possibly Jack Schwartz (who at least appeared on We Have Arrived). Lee Rauch has the dubious honor of being this trope not only for Dark Angel but also to Megadeth, having played on a demo with them and nothing else.
- What Could Have Been:
- Dave Mustaine had asked Eric Meyer to join Megadeth several times, declining each and every time to stick with Dark Angel. He also hit up Durkin about joining, but the latter declined because he didn't want to give up Dark Angel (though, like Lee Altus and probably Meyer as well, Mustaine's out-of-control drug usage probably played a role in this decision).
- A fifth album, The Atrocity Exhibit, was planned back in 1992 but never came into frution. Interestingly, Exodus would release an album with the same title fifteen years later.