Polsloe Priory, also known as St Katherine's Priory, was a Benedictine priory for women (a nunnery) in Devon, England. It was founded in around 1159 on land to the east of Exeter, on a site that is now part of the city's suburb of Polsloe. At the time it was the only religious house for women in Devon, but two others were founded later: at Cornworthy and Canonsleigh Abbey. The first prioress of whom any record survives was Avelina in 1218. Amongst the holdings of the priory was the Church of St Mary, Marston Magna in Somerset.