Annalong (from Irish: Áth na Long) is a seaside village in County Down, Northern Ireland at the foot of the Mourne Mountains. The village was once engaged in exporting dressed granite and is now a fishing and holiday resort.

Its Marine Park offers a unique combination of facilities to enable the visitor to have an unforgettable day out whatever the weather. Besides being able to launch a boat at all states of the tide, the visitor may also view the Herb Garden , follow the Marine Park Trail, , picnic overlooking the harbour whilst keeping an eye on the children at play and take in an exhibition at the Visitors Centre. There are ample car and coach park facilities and a short-stay caravan park and campsite. The village of Annalong can be easily reached over a footbridge, and one can also enjoy a stroll along the Mourne Coastal Path

Annalong Cornmill was built in the 19th century and operated until the 1960s and was one of the last working watermills in Northern Ireland. It contains a grain drying kiln and three pairs of millstones. It is powered by a 15 ft water wheel and a 1920s Marshall “hot-bulb” 20hp engine. Restoration began in 1983 after it was acquired by Newry and Mourne District Council, and it reopened in 1985.

Annalong harbour has received some regeneration over the past number of years. It dates back to the early 19th century and in later years was made bigger to receive schooners carrying granite to English cities and to import materials used to build the nearby dam at the Silent Valley. The harbour was enlarged in the 1880s to cope with the increased granite exports.