Gelmir can refer to:
 Elves of the First Age
- Gelmir (son of Guilin), son of Guilin who was captured by Morgoth's servants in the Dagor Bragollach.
- Gelmir (messenger of Círdan), a Noldorin Elf sent by Círdan as a messenger to Nargothrond.
 Earlier Writings
Other characters who were named Gelmir in earlier writings:
- Arminas, companion of Gelmir (messenger of Círdan), who was named Gelmir in earlier writings.
- Finwë, father of Fingolfin, who was named Gelmir in the Lay of the Fall of Gondolin.