君士坦丁大帝（英文Constantine the Great ，拉丁文Flavius Valerius Aurelius Constantinus Augustus； 約莫272年2月27號—337年5月22號），亦叫君士坦丁一世（Constantine I）或者聖君士坦丁（Saint Constantine），係羅馬皇帝，在位公元三百零六年到三百卅七年。 佢出名原因皆因佢係第一個羅馬皇帝轉信基督敎。三百一十三年，君士坦丁同副皇帝李西諾發米蘭上喻（Edict of Milan），公告全國，全有宗敎皆可容許在國。
- In Classical Latin, Constantine's official imperial title was IMPERATOR CAESAR FLAVIVS CONSTANTINVS PIVS FELIX INVICTVS AVGVSTVS, Imperator Caesar Flavius Constantine Augustus, the pious, the fortunate, the undefeated. After 312, he added MAXIMVS ("the greatest"), and after 325 replaced ("undefeated") with VICTOR, as invictus reminded many of Sol Invictus, the Sun God.
- Birth dates vary but most modern historians use c. 272". Lenski, "Reign of Constantine" (CC), 59.
- Among Eastern Orthodox, Oriental Orthodox and Byzantine Catholic Christians. The Byzantine liturgical calendar, observed by the Eastern Orthodox Church and Eastern Catholic Churches of Byzantine rite, lists both Constantine and his mother Helena as saints. Although he is not included in the Latin Church's list of saints, which does recognise several other Constantines as saints, he is revered under the title "The Great" for his contributions to Christianity.
- I. Shahîd, Rome and the Arabs (Washington, D.C.: Dumbarton Oaks, 1984), 65–93; H. A. Pohlsander, "Philip the Arab and Christianity", Historia 29:4 (1980): 463–73.