Øyer is a municipality in Oppland county, Norway. It is part of the traditional region of Gudbrandsdal. The administrative centre of the municipality is the village of Tingberg.

In English law, Oyer and terminer (; a partial translation of the Anglo-French oyer et terminer which literally means "to hear and determine") was the Law French name for one of the commissions by which a judge of assize sat. The commission was also known as audiendo et terminando.