 It has a population of 5,566 inhabitants as of 2016

Historically what is now Harmonstown was mostly in Raheny.The locality is bounded by the railway cutting, the Santry River within the Springdale Road Linear Park, and Brookwood Avenue.Harmonstown is located south of Artane and Coolock, and is accessed by a railway bridge from the Ennafort / Cill Eanna part of Raheny, and faces the Edenmore part.