Mariangelo Accorso (Latin: Mariangelo Accursio or Mariangelus Accursius; 1489 or 1490 - 1544 or 1546) was an Italian writer and critic. He was born at L'Aquila (Abruzzo); then part of the kingdom of Naples.

Accorso was a great favourite with Charles V; at whose court he resided for thirty-three years; and by whom he was employed on various foreign missions. To a perfect knowledge of Greek and Latin he added an intimate acquaintance with several modern languages.

In discovering and collating ancient manuscripts; for which his travels abroad gave him special opportunities; he displayed uncommon diligence. His work entitled Diatribae in Ausonium; Solinum et Ovidium (1524) is a monument of erudition and critical skill.