Gregorio Ricci-Curbastro (12 January 1853 - 6 August 1925) was an Italian mathematician.

He was born at Lugo di Romagna. He is most famous as the inventor of the tensor calculus but published important works in many fields. His most famous single publication, The Absolute Differential Calculus, was published under the name Ricci and co-authored by his former student Tullio Levi-Civita. This appears to be the only time that Ricci-Curbastro used the shortened form of his name in a publication, and continues to cause confusion.