* AdoredByTheNetwork: The show never does very well in ratings, but is pushed very heavily by HBO and renewed for later seasons despite this.
* CelebrityParadox: In the season 4 premiere, Shoshanna compares Adam, who has become an actor, to Armie Hammer and Creator/ZacharyQuinto. Quinto appears later in the season as Mimi-Rose Howard's ex-boyfriend Ace.
* CopiouslyCreditedCreator: Created, written, directed by, and starring Lena Dunham.
* TheDanza: Both the character (Sackler) and the actor who plays him (Driver) are named Adam.
* DirectedByCastMember / WrittenByCastMember: Lena Dunham (Hannah) created the show and also writes and directs many episodes (especially in the 1st season).
* FakeNationality: American Thomas-John is played by Irish comedian and actor Chris O'Dowd.
* HeyItsThatGuy:
** Shoshanna, Shoshanna...to think that [[Series/MadMen in another life]], you were a confident, lesbian, ''real'' Bohemian photo editor at ''Life''.
** Looks like [[Film/TheForceAwakens Kylo Ren]] used to be a struggling actor before he embraced the dark side.
** The artist who propositions Marnie at the gallery is [[TheLonelyIsland Jorma Taccone]].
** Apparently [[Series/TheSopranos Christopher]] used to be Hannah's professor
** [[Series/FreaksAndGeeks Mrs. Weir]] and [[HoneyIShrunkTheKids Wayne]] are married college professors and Hannah is their child.
** {{Series/Community}}'s Troy briefly dated Hannah.
** Holly crap, [[Film/WithnailAndI Withnail]] is in rehab!
** Looks like Hannah and [[{{Spanglish}} Bernice are related]].
** Despite playing a SoOkayItsAverage singer in this show, in reality, Marnie's got some impressive pipes on her. How impressive? [[Theatre/PeterPan She played the lead in NBC's 2014 live adaption of Peter Pan]]!
* RealitySubtext: [[http://www.newyorker.com/online/blogs/culture/2013/02/that-sex-scene-on-last-nights-girls.html This article]] suggests that Hannah and Sandy's conversation about her essay (he says nothing happens, she argues that what happens is that "a girl’s whole perspective on who she was, and her sexuality, changed") could be a pre-emptive response to criticism of the episode "One Man's Trash." Though it could just as well apply to several other episodes, or the series as a whole.
* WriteWhoYouKnow: Dunham has OCD, is a writer, has made bad life choices, lost financial support from her parents, and is a mere 2 years older than her character.