Clare is a maritime county in the province of Munster, bounded on the west by the Atlantic, on the north-west by Galway Bay, and on the east and south by the river Shannon. The present county formed, from a very early period, a native principality, Tuath-Mumhan, or Thomond, signifying "North Munster." The area was divided into cantreds or baronies, each occupied by their ruling families. The O'Loughlins, O'Garbhs, O'Briens, O'Connors, O'Deas, McMahons, and McNamaras were the main clans. Together, these families are generally referred to as the Dalcassian families, from Dal gCais, a name for the eastern half of the county.

The O'Briens were a major force in Thomond from earliest times. The Danish Vikings raided this county on many occasions during the 9th and 10th centuries. They were finally defeated at the beginning of the 11th century by the most famous of the O'Briens, Brian Boru, who also led the army which defeated the Danes of Dublin at Clontarf in 1014.

Following the Norman invasion, Thomond was granted to Thomas de Clare who attempted to take control of the county but was eventually defeated by the O'Briens. The O'Briens were later made Earls of Thomond and thereby remained the major force in the county for centuries. The county boundaries were established by the English administration in 1565.

Following the defeat of the 1641 rebellion of the Catholic Confederacy, Clare was set aside to accommodate the "delinquent proprietors," i.e. those proprietors whose land was confiscated because they did not actively oppose the rebellion. Parts of the lands of the existing Clare landholders were confiscated to accommodate these landholders.

The county was badly affected by the Great Famine of 1845-47. The population was 286,000 in 1841 and by 1851 had been reduced to 212,000. Over 50,000 people died between 1845 and 1850 and many emigrated, mainly to Australia. The decline in population continued during the subsequent one hundred years, falling to 73,500 in 1966. A gradual increase has been occurring since then and the 1991 census recorded a population of 91,000.

The abundance of antiquities and archaeological remains which are scattered throughout the county are a legacy to the lives of its historic and pre-historic inhabitants. County Clare has at least 2,300 earthen and stone forts, 130 megalithic tombs, 190 castles, 150 ancient churches, 3 cathedrals, 8 monasteries, 10 stone crosses, 5 round towers, besides numerous lesser monuments.

The county is fortunate in having areas of great natural beauty and superb scenery with many sandy beaches and sheltered bays. Loop Head is the most exposed promontory on the west coast and is of geological interest with some unusual rock formations. The near-by Bridges of Ross were formed by storm waves channelling into the caverns and creating natural arches which in time became separated from the mainland. The coast road around Black Head is an attractive touring route, bounded on one side by the Atlantic and the Aran Islands, and on the other by the grey hills of the Burren. The Burren region comprises 375 square miles of gently sloping carboniferous limestone landscape upon which many rare and beautiful plants thrive. The area is favoured by cavers and potholers as well as those interested in archaeology.

The majesty of the Cliffs of Moher is well known. The cliffs are also a favourite nesting ground for flocks of sea birds and up to fifty species can be seen. These include fulmars, gannets, guillemots, shags, cloughs and puffins.

In complete contrast, east Clare offers more gentle countryside, with many inviting lakes and streams. The river Shannon, and the vast expanse of Lough Derg, are host to boating and watersports of all kinds.

John Lloyd said of County Clare in 1780, "From its agreeable situation, the climate is remarkably wholesome, the air clear and temperate, and the prospect pure and delightful." Little has happened during the past two centuries to change this description. County Clare today is a place of great natural beauty and historical and archaeological interest while offering a range of amenities to suit all tastes.