Agathangelus is the Latinized form of the Greek name Agathangelos (Greek: Αγαθάγγελος).
Agathangelus or Agathangelos is the name of:
- Agathangelus of Rome (died 312), Christian martyr
- Agathangelos (c. 5th century CE), possibly a pseudonym, the biographer of Gregory the Illuminator
- Agathangelus of Constantinople (1769–1832), Patriarch of Constantinople
- Agathangelos Xirouchakis (1872–1958), Greek Orthodox cleric and historian
- Agathangelos Tsiripidis (born 1963), Greek boxer