Michael Thomas Christopher Mallin (Irish: Micheál Ó Mealláin; 1 December 1874 – 8 May 1916) was an Irish republican, Socialist and devout Catholic who took an active role in the Easter Rising of 1916.
He was a silk weaver, the co-founder with Francis Sheehy-Skeffington of the Socialist Party of Ireland, and was second-in-command of the Irish Citizen Army under James Connolly in the Easter Rising, in which he commanded the garrison at St.