IDK is a three-letter initialism or abbreviation which may refer to:
Music
- IDK (rapper), British-American rapper
- "IDK" (song), a 2020 song by Lil Tecca
- "IDK Y", a 2022 song by Joel Deleōn
Other uses
- Abbreviation for I Don't Know
- Indulkana Airport (IATA: IDK), in Indulkana, South Australia, Australia; see List of airports by IATA airport code: I
- Internationale der Kriegsdienstgegner/innen, the German section of War Resisters' International
See also
- All pages with titles containing IDK