* ActingforTwo: some X5s have [[CloningBlues clones]], such as Ben's clone Alec (both are played by JensenAckles) and Max's clone Sam (both are played by Jessica Alba).
** Joshua had a younger brother named Isaac, who was also played by Creator/KevinDurand.
** Geneva Locke played both Max's younger self in flashbacks and her X7 clone in the present.
* DevelopmentGag: 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.
* ExecutiveMeddling: 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.
* FridayNightDeathSlot: Shipped here in its second season. The show that replaced it in that particular timeslot? Firefly. Cue fan-war.
* HeyItsThatGuy:
** Nana Visitor AKA Major Kira Nerys from Deep Space Nine as Madame X/Dr. Elizabeth Renfro
** John Savage as Lydecker counts for anyone who's seen ''Film/TheDeerHunter''.
** Hey! [[Series/{{NCIS}} Tony DiNozzo]] is Logan! And Michael Weatherly has said he was inspired by ''Dark Angel'''s Alec.
** ''Series/{{Battlestar Galactica|2003}}'': Sharon/Boomer (Grace Park) as a female breeding X5, Leoben (Callum Keith Rennie) as a sheriff, Chief Tyrol (Aaron Douglas) as a hotel manager, Tory (Rekha Sharma) as Dr. Beverly Shankar, Crashdown (SamWitwer) as a transgenic named Marrow, Cally (Nicki Clyne) as an X6 named Fixit, Dualla (Kandyse [=McClure=]) as Joshua's girlfriend Annie Fisher, Narcho (Sebastian Spence) as Tinga's husband Charlie Smith, Elosha (Lorena Gale) as a teacher, Simon (Rick Worthy) as Detective Ramon Clemente, Gaeta (Alessandro Juliani) as Max's work friend Druid.
*** Grace Park is the only actor to have played both a transgenic and a Cylon.
** ''Series/{{Caprica}}'': Agent Durham (Brian Markinson) as Dr. Sam Carr.
** ''Series/{{The Office|US}}'': Dwight Schrute (Rainn Wilson) as Phil, the "superhero" who gave Logan his exoskeleton.
** ''Series/{{Supernatural}}'': Mary Winchester (Samantha Smith) as Logan's ex-fiancée Daphne. Meg Masters (Nicki Aycox) as Max's sister Syl.
*** This is funny, as it means JensenAckles and Nicki Aycox, in addition to playing enemies on ''Series/{{Supernatural}}'', have played brother and sister on ''DarkAngel'', although Ben and Syl didn't appear onscreen together.
*** If we're going down that route, then this also means that Max's love interest was engaged to the woman who becomes the mother of her ''sort of'' ''[[{{VitriolicBestBuds}} partner-in-crime]]''. And considering it's a bit of a running gag in the fandom (especially of Alex/Max shippers) that Logan was a lot older than then 19y/o Max, having Mama!Winchester his ex-fiancée just about proved the point.
* RomanceOnTheSet: Jessica Alba (Max) and Michael Weatherly (Logan). They were engaged.
* SimilarlyNamedWorks: 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.
* StarMakingRole: For Jessica Alba.