County Westmeath, situated in the Irish Midlands in the western part of Leinster, is popularly called the "Lake county" and the "great county." The county was once part of the ancient province of Meath and later of County Meath. The association was ended in 1543 when County Westmeath was created under the Counties of Meath and Westmeath Act.

Mullingar with a population 18,529 is the urban and county administrative centre, while being the largest ubban district of the county. Athlone (population 16,888), Mote, Kilbeggan, and Castlepollard are also important commerce and marketing urban activity centres within the county.

The county is famous for its cattle; lakes such as Lough Derravaragh, Lough Ennell, Lough Lene, Lough Owel. and Lough Ree; pewter such as Mullingar Pewter; scenery; and the canal. It is rapidly becoming part of the outer commuter belt of Dublin.

Castles, monuments and ancient sites are abundant in County Westmeath. The renowned Irish fable, Children of Lir, is the Tuatha de Danann legend of Lough Derravaragh. The Hill of Uisneach, near Ballymore, was once the ancient seat of the Kings of Meath with its history rooted in the Iron Age. Westmeath boasts of magnificent castles and gardens including Ballinlough Castle Gardens, Tullynally Castle, and St. Feichins Monastery at Fore - dating back to the 7th century. Tullynally Castle, one of Ireland's largest castles, is a huge structure adorned with numerous turrets and battlements.

Locke's Distillery Museum and Athlete Castle Visitor Centre are both premier heritage destinations in the county.

According to the Irish Independent, 12 December 2006, Westmeath is the goat capital of Ireland, with five times as many goats as Kerry.

Uisnech Hill is considered the omphalos (mystical navel) of Éire (Ireland), whereupon rests a great stone (Ail na Mírenn, which means “stone of divisions”) marked with lines indicating the provincial borders of Connacht, Leinster, Ulster and Munster. Tradition tells that Uisnech was a site favored for Beltane fires and Druidical ceremonies, in fact being considered second only to Emain Macha. In the poetic history Lebor Gabála (“Book of Invasions”), the Nemedian Druid Mide lit the first fire there.

According to a popular passage from the same record, Ériu, a tutelary goddess sometimes considered the personification of Éire, meets the invading Milesians at Uisnech hill, where after some conversation and drama the Milesian poet Amairgin promises to give the country her name. Geoffrey of Monmouth's Historia Regum Britanniae (History of the Kings of Britain) claims a common belief that Stonehenge was transported to Britain from Uisnech. St. Brigid of Christian legend, who is also notably connected with fire, took the veil at this sacred locus.

A fire was lit on the Hill of Uisneach on the feast of Bealtine. This fire could be seen from Tara and when they saw it they lit their fire.