The High Sheriff of Westmeath was the British Crown's judicial representative in County Westmeath, Ireland from its creation under The Counties of Meath and Westmeath Act 1543 until 1922, when the office was abolished in the new Free State and replaced by the office of Westmeath County Sheriff. The sheriff had judicial, electoral, ceremonial and administrative functions and executed High Court Writs. In 1908, an Order in Council made the Lord-Lieutenant the Sovereign's prime representative in a county and reduced the High Sheriff's precedence. However the sheriff retained his responsibilities for the preservation of law and order in the county. The usual procedure for appointing the sheriff from 1660 onwards was that three persons were nominated at the beginning of each year from the county and the Lord Lieutenant then appointed his choice as High Sheriff for the remainder of the year. Often the other nominees were appointed as under-sheriffs. Sometimes a sheriff did not fulfil his entire term through death or other event and another sheriff was then appointed for the remainder of the year. The dates given hereunder are the dates of appointment. The following is an incomplete list: all addresses are in County Westmeath unless stated otherwise.

High Sheriffs of County Westmeath

Anne, 1702–1714

George I, 1714–1727

George II, 1727–1760

George III, 1760–1820

George IV, 1820–1830

William IV, 1830–1837

Victoria, 1837–1901

Edward VII, 1901–1910

George V, 1910–1922