Portstewart is a small town in County Londonderry, Northern Ireland. It had a population of 7,854 people in the 2021 Census. It is a seaside resort neighbouring Portrush. Its harbour and scenic coastal paths form an Atlantic promenade leading to a two-miles beach, popular with holidaymakers in summer and surfers year-round.

County Londonderry, also known as County Derry, is one of the six counties of Northern Ireland, one of the thirty-two counties of Ireland and one of the nine counties of Ulster. Before the partition of Ireland, it was one of the counties of the Kingdom of Ireland from 1613 onward and then of the United Kingdom after the Acts of Union 1800. Adjoining the north-west shore of Lough Neagh, the county covers an area of 2,118 km2 (818 sq mi) and today has a population of about 252,231.