| Native Name: | Διοίκησις Μακεδονίας |
| Conventional Long Name: | Diocese of Macedonia |
| Common Name: | Macedonia |
| Subdivision: | Diocese |
| Nation: | the Roman Empire |
| Era: | Late Antiquity |
| Capital: | Thessalonica |
| Title Leader: | Vicarius |
| Life Span: | 306–7th century |
| Year Start: | 306 |
| Event Start: | Reforms of Diocletian |
| Year End: | 7th century |
| Event End: | Slavic invasion of the Balkans |
| Event1: | Thessalonica became the Prefecture's new capital city |
| Date Event1: | 379 |
| Today: |  Albania Greece Bulgaria |
The Diocese of Macedonia (la|Dioecesis Macedoniae; el|Διοίκησις Μακεδονίας) was a diocese of the later Roman Empire, forming part of the praetorian prefecture of Illyricum. Its administrative centre was Thessalonica.
The diocese was formed, probably under Constantine I (r. 306–337), from the division of the Diocletianic Diocese of Moesia. It included the provinces of Macedonia Prima, Macedonia Salutaris, Thessalia, Epirus vetus, Epirus nova, Achaea, and Crete. Alongside Dacia and, until 379, Pannonia, it made up the Prefecture of Illyricum. In 379, Pannonia was detached and merged into the Praetorian prefecture of Italy and Thessaloniki became the Prefecture's new capital city instead of Sirmium.