He was educated at Gloucester Hall, Oxford where he graduated BA in 1568, MA in 1572 and BD in 1585.
He was appointed:
- Vicar of St Clears, Carmarthen 1577
- Rector of Ham, Wiltshire 1582
- Rector of Bletchingdon, Oxfordshire 1583
- Archdeacon of Buckingham 1589
- Rector of West Ilsley, Berkshire 1601–1613
He was appointed to the ninth stall in St George's Chapel, Windsor Castle in 1590, a position he held until 1614.
He was buried in the chapel. His inscription read:
"Hic jacet Erasmus Webb, Sacrae Theologiae Baccalaureus, cujus Regiae Capallae quondam Canonicus, qui obit 24 die Martii, Anno Domini 1613. Aetatis suae 63”
- Fasti Wyndesorienses, May 1950. S. L. Ollard. Published by the Dean and Canons of St George's Chapel, Windsor Castle
- A Survey of the Cathedrals of York, Durham, Carlisle, Chester, Man, Litchfield, Hereford, Worcester, Gloucester, Bristol, Lincoln, Ely, Oxford, Peterborough, Canterbury, Rochards, London, Winchester, Chichester, Norwick, Bangor and St Asaph. Brown Willis. Dublin. 1742