Ballyclare (from Irish Bealach Cláir, meaning 'pass of the plain'^ⓘ) is a town in County Antrim, Northern Ireland. It had a population of 10,850 according to the 2021 census, and is located within the Antrim and Newtownabbey Borough Council area. It is part of, and the principal settlement in the Ballyclare District Electoral Area.

It sits on the river Six Mile Water. The town probably owes its origins to its being a crossing point of the river, the strategic importance of which is shown by existence of a small Norman motte on the south side of the river and presently located in the War Memorial Park. The broad main street dates from the 17th century. In the centre of the town is the Market Square with the Town Hall. The town grew in the 19th century with the coming of the railway and it became an important industrial town with a large paper mill in the South West of the town and a large Linen Bleach Green. These factories gave their names to the roads leading to them, the Mill Road and the Green Road, but have been closed for some time. It is now a local service centre with a significant dormitory role in relation to Belfast. It is the main focus within the rural area for shopping, education and recreation. To the north is the remnant of Craig Hill, which once provided a wooded backdrop but is now covered with modern housing. Much of the Craig Hill has been quarried for its basalt.

People have lived in Ballyclare for six thousand years. The earliest evidence of people in this area is a hoard of flint arrow heads found when houses were being built north of the river in November 1968. There were a total of thirty-nine flints discovered – some perfectly finished and others are blank indicating an 'industry' and trading here near the river crossing over four thousand years ago.

When the Normans built the castle at Carrickfergus they placed a line of outposts along the river which was then called the "Ollar" – River of the Rushes. In time the soldiers making the journey from Carrickfergus to Antrim reached the river at this spot when they had travelled six miles so began to call the Ollar the Six Mile Water. One of these mottes is close by the river in the War Memorial Park in Ballyclare. There are two on opposite sides of the river at Doagh and one at Antrim. The village grew after the Plantation of Ulster and was granted permission by King George II in 1756 to hold two fairs each year making it an important market centre.

At the same time as the Pilgrim Fathers landed in what is now the United States, Ballyclare was settled by Scots planters. Jonathan Swift preached in Ballyclare and it was from the town that the families of Mark Twain, Sam Houston and General Alexander Macomb left for America. The people of Ballyclare and the surrounding villages played a part in the Irish Rebellion of 1798, and fought in the Battle of Antrim. At the beginning of the 20th century Ballyclare was a growing industrial town with an urban district council and became the largest paper producer in Ireland.

As part of the 1947 Grand Prix season, which constituted the first full season of the FIA's Formula One motor racing, the 1947 Ulster Trophy race took place at Ballyclare.

As of the 2021 census, there were 10,850 people living in Ballyclare (4,614 households), an increase of 9% on the 2011 census population of 9,953.

In the 2021 census the demographics of the town was as follows: