Holywood, a seaport of county Down, Ireland, on the east shore of Belfast Lough, 4½ m. N.E. from Belfast by the Belfast & County Down railway. Its pleasant situation renders it a favourite residential locality of the wealthier classes in Belfast. There was a religious settlement here from the 7th century, which subsequently became a Franciscan monastery. The old church dating from the late 12th or early 13th century marks its site. A Solemn League and Covenant was signed here in 1644 for the defence of the kingdom, and the document is preserved at Belfast.