Howth Castle and estate lie just outside the village of Howth, County Dublin in Ireland, in the administration of Fingal County Council. The castle was the ancestral home of the line of the St Lawrence family that had held the area since the Norman Invasion of 1180, and held the title of Lord of Howth until circa 1425, the Baron Howth to 1767, then Earl of Howth until 1909. The castle and estate are held since 1909 by their distaff heirs, the Gaisford-St Lawrence family.

The Howth Tram on the Hill of Howth Tramway was a tram which served Howth Head, near Dublin, Ireland. The termini were at Sutton railway station, by the entrance to the peninsula, and Howth railway station by the village and harbour of Howth.