Roger Mortimer, 1st Earl of March, English politician, Lord Lieutenant of Ireland (died 1330)

Roger Mortimer, 3rd Baron Mortimer of Wigmore, 1st Earl of March, was an English nobleman and powerful marcher lord who gained many estates in the Welsh Marches and Ireland following his advantageous marriage to the wealthy heiress Joan de Geneville, 2nd Baroness Geneville. Her mother was of the royal House of Lusignan. In November 1316, he was appointed Lord Lieutenant of Ireland. He was imprisoned in the Tower of London in 1322 for having led the marcher lords in a revolt against King Edward II in what became known as the Despenser War.

Lord Lieutenant of Ireland, or more formally Lieutenant General and General Governor of Ireland, was the title of the chief governor of Ireland from the Williamite Wars of 1690 until the Partition of Ireland in 1922. This spanned the Kingdom of Ireland (1541–1800) and the United Kingdom of Great Britain and Ireland (1801–1922). The office, under its various names, was often more generally known as the Viceroy, and his wife was known as the vicereine. The government of Ireland in practice was usually in the hands of the Lord Deputy up to the 17th century, and later of the Chief Secretary for Ireland.