The council is responsible for housing and community, roads and transportation, urban planning and development, amenity and culture, and environment.

Originally Westmeath County Council held its meetings in Mullingar Courthouse.

[1] The council commissioned a purpose-built facility, known as County Hall, in Mount Street in Mullingar in the early 20th century.

[2] In the early part of the 21st century it occupied a historic building on the same site associated with the old county gaol.

[5] Members of Westmeath County Council are elected for a five-year term of office on the electoral system of proportional representation by means of the single transferable vote (PR-STV) from multi-member local electoral areas (LEAs).