Howth is located on the peninsula of Howth Head, which begins around 13 kilometres (8.1 mi) east-north-east of Dublin, on the north side of Dublin Bay. The village itself is located 15 kilometres (9.3 mi) from Dublin city centre (the ninth of a series of eighteenth century milestones from the Dublin General Post Office (GPO) is in the village itself), and spans most of the northern part of Howth Head, which was once an island but now is connected to the rest of Dublin via a narrow strip of land (tombolo) at Sutton. Howth is located in the administrative county of Fingal.
Howth is at the end of a regional road (R105) from Dublin and is one of the two northern termini of the DART suburban rail system. Dublin Bus also serves Howth with route 31 and its variants.