Roundwood (Irish: An Tochar, meaning The Causeway) is a village in County Wicklow, Ireland. It was listed as having a population of 518 in the census of 2002. It is located on the R755 road which is part of the main route from Dublin to Glendalough in the Wicklow Mountains. At 238 metres above sea level, it is one of the highest villages in Ireland.
Roundwood has a close association with two former Presidents of Ireland, Seán T. O’Kelly who lived locally and Erskine Childers who is buried in Derralossary Churchyard near the village. Vartry Reservoir Lakes (reservoirs built in the 1860s) are close by.