Theodemir, Theodemar, Theudemer or Theudimer was a Germanic name common among the various Germanic peoples of early medieval Europe. According to Smaragdus of Saint-Mihiel (9th century), the form Theudemar is Frankish and Theudemir is Gothic.
- Theodemer (Frankish king), early 5th century
- Theodemir (Ostrogothic king) (died 475), Ostrogothic king
- Theodemir (Suebian king) (died 570), Suevic King of Galicia
- Theodemir (Visigoth) (died 743), Visigothic nobleman
- Theodemir (saint) (died 851), Spanish saint
- Theodemar of Monte Cassino (fl. late 8th century), abbot of Monte Cassino
- Theodemir of Iria (died 847), bishop of Iria Flavia
- Theodemir (bishop of Mondoñedo), flourished 972–77
- W. Haubrichs, in discussion of D. H. Green (2007), "Linguistic and Literary Traces of the Ostrogoths", The Ostrogoths from the Migration Period to the Sixth Century: An Ethnographic Perspective, Sam J. Barnish and Federico Marazzi, edd., part of Studies in Historical Archaeoethnology, Volume 7, Giorgio Ausenda, series ed. (Oxford: Boydell Press, ISBN 978-1-84383-074-0.), p. 409.