Richard Ó Madadhan (c. 1620 – late 1691) was Prior of Portumna Priory in 1691.
He studied at Avila but could not return to Ireland because of the Cromwellian Wars.
Their establishment was erected into a priory in 1640 under Ambrose Ó Madadhan but they were forced to abandon it during the Cromwellian era.
However, he and the rest of the community were obliged to abandon the area in the aftermath of the Battle of Aughrim in July 1691.
Hunted by Williamite forces, Ó Madadhan fled into "an impassable bog" but ultimately died of starvation.