Crofton was born in County Roscommon and educated at Trinity College, Dublin.[2] Crofton was ordained in 1641. He was a prebendary of Elphin Cathedral from 1661 to 1668,[3]and of St Patrick's Cathedral, Dublin from 1662;[4] and Dean of Elphin[5] from 1665[6] holding the latter two positions until his death in 1683.