* 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''.
** The artist who propositions Marnie at the gallery is [[TheLonelyIsland Jorma Taccone]].
** Apparently [[TheSopranos Christopher]] used to be Hannah's professor
** [[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]]!
* 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.