Tomás Antonio Ignacio O'Horán y Escudero (1819-1867) was an Imperial Mexican general of Irish descent during the Second French intervention in Mexico.

Initially given the nickname "the Immortal of Atlixco", he managed to repel Imperial Mexican forces along with General Antonio Carvajal which played a significant role in the Republican victory during the Battle of Puebla.

During the battle, his liberal friend Antonio Taboada asked O'Horán if he would like to switch sides, claiming that if he did so, that Mexico would be brought to stability but he declined at the moment.

However, after the Republican forces evacuated Central Mexico and in a difficult employment position, O'Horán defected to the Imperial Mexican Army and managed to quell the unrest at Tlalpan.

He then wrote a manifesto, claiming that he simply wanted to bring order to Mexico, never intended to back the interests of foreign powers and did not deserve death for a political error due to his prior service in serving the country.