Nyssa (Ancient Greek: Νύσσα) was a town and bishopric in Cappadocia, Asia Minor.

It is important in the history of Christianity due to being the see of the prominent 4th century bishop Gregory of Nyssa.

Ptolemy's Geography places it at 68°20' 38°40 (in his degrees) in the Prefecture of Murimene (Ancient Greek: Στρατηγίας Μουριμηνῆς).

[2] The site of Nyssa has been identified as near the modern town of Harmandalı, Ortaköy district, Aksaray province, in south-central Turkey.

[6][7] The Eastern Orthodox Church has continued to appoint titular bishops of Nyssa even after the town and its Christian community ceased to exist.