Karekin Pastermadjian (classical Armenian: Գարեգին Փաստրմաճեան), better known by his nom de guerre Armen Garo (Արմեն Գարո), was an Armenian nationalist activist and politician. A member of the Armenian Revolutionary Federation, he was one of the masterminds of the 1896 occupation of the Ottoman Bank in response to the Hamidian massacres and Operation Nemesis, in which several perpetrators of the Armenian Genocide were assassinated.