The Greco-Roman name Dionysius, deriving from the name of the god Dionysos or Dionysus, was exceedingly common, and many ancient people, famous and otherwise, bore it. It remains a common name today in the form Dennis (Denys, Denis).

Among the historical figures known by the name Dionysius, some of the more famous were:

• Dionysius the Elder (or Dionysius I), a ruler of Syracuse in Sicily
• Dionysius the Younger, (or Dionysius II), son of the preceding
• Dionysius Periegetes, Greek geographer, 3d century BC
• Dionysius Thrax, Greek grammarian, 2d century BC
• Dionysius the Areopagite, an Athenian judge who was converted by Paul of Tarsus and became Bishop of Athens
  • Pseudo-Dionysius the Areopagite, (5th century) name given to anonymous writer, identified by some with a Georgian theologian Peter the Iberian (411‑491), author of Corpus Areopagiticum (see also pseudepigrapha)
• Dionysius the Philosopher, (1560 AD - 1611 AD) an Epirotian Greek monk who led two farmer revolts against the Ottoman Turks.
• Dionysius of Halicarnassus, a Greek historian of the Roman period
• Saint Dionysius of Alexandria, 3rd century Egyptian bishop
• Saint Denis, Bishop of Paris, martyr (died ca. 250)
• Pope Dionysius (259 - 268)
• Dionysius Exiguus, (c. 470 – c. 540) a Dacian monk who invented the Anno Domini era
• Dionysius Telmaharensis, (d. 848) a former head of the Syrian Jacobite Church
• Jacob Bar-Salibi also know as Dionysius Bar-salibi was a member of Syrian Jacobite Church in the 12th century, best know for his commentary on biblical texts
• Dionysius the Wise, (lt. 15th - ea. 16th cen.) the Russian medieval icon-painter
• Dionysius I, Metropolitan of Moscow (c. 1300 - 1385) a 14th century orthodox prelate
• Benjamin Musaphia (1606 - 1675) a Jewish doctor, scholar, and kabbalist, who sometimes called himself Dionysius.
• Dionysius Lardner (1793 - 1859) an Irish scientific writer
• Demetis Dionisis, musician

Dionysios | Denys | דיוניסיוס | Dionysius | Dionísio (desambiguação) | Dionysios