Langavatn
Langavatn stands for:
- a lake in the Icelandic municipality of Borgarbyggð in western Iceland, see Langavatn (Borgarbyggð)
- a lake in the Icelandic municipality of Mosfellsbær (and partly Reykjavíkurborg) in western Iceland, see Langavatn (Mosfellsbær)
- a lake in the Icelandic municipality of Skagabyggð in northern Iceland, see Langavatn (Skagabyggð)