Mario Guiducci (1585–1646) was an Italian astronomer and jurist, born in Florence. He studied law for some time at Pisa University. Discorso Delle Comete, 1619, was published under Mario's name. However, this was mostly a work by Galileo Galilei. Galileo and Mario cooperated for some time, and this cooperation was particularly notable between 1618 and 1623, known as the time of the dispute on the comets.