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Demetrius of Thessaloniki
Christian martyr (died 306)
SaintFull write-upPre-congregation
Feast: 9 April (not on the universal Roman calendar; kept in the Roman Martyrology or local calendars)
Born
300
Died
306
Beatified
—
not needed: before formal processes
Canonised
By tradition
recognised before formal processes began
Who they were
Near Srijem in Pannonia, in present-day Croatia, Saint Demetrius, martyr, who enjoys devout veneration everywhere in the East, and in particular at Thessaloniki.
The miracles
There was never a formal cause: he has been honoured as a saint since before the Church's formal processes began.
Why that counted as sanctity
The Roman Martyrology remembers him on 9 April as a martyr of Srijem venerated throughout the East, especially at Thessaloniki.
Sources
- Roman Martyrology, 9 April (Italian Bishops' Conference, Santo del giorno)
- Wikidata Q310633 — dates, feast day and identifiers (CC0)
- English Wikipedia — Demetrius of Thessaloniki (CC BY-SA)
Checked against the sources listed on 22 September 2026. Corrections welcome.