Easby Abbey, or the Abbey of St Agatha, is a ruined Premonstratensian abbey on the eastern bank of the River Swale on the outskirts of Richmond in the Richmondshire district of North Yorkshire, England. The site is privately owned but maintained by English Heritage and can be reached by a riverside walk from Richmond Castle. Within the precinct is the still-active parish church, displaying 13th-century wall paintings.