Marzio di Colantonio or di Colantonio Ganassini or di Cola Antonio (c. 1580s – after 1623) was an Italian painter, as a painter of still-lifes and landscapes, and fresco decorations of grotteschi and battle scenes with small figures. His still-life paintings contain hunted game.
He was born in Rome, and trained initially under his father, a painter of Grotteschi. He is said to have then trained under Antonio Tempesta.
He painted some sacred subjects including frescoes for the church of Santa Maria della Consolazione of Rome, he was best known for his battle paintings, for which he was recruited by the Cardinal of Savoy to work for a time in Piedmont for the House of Savoy. He died young in Viterbo.