A clothier by trade, Swaddon was already a prominent Calne burgess by 1561, the first year in which he is known to have served as guild steward. He subsequently held this office four more times, and in that capacity presided over the borough’s 1588 and 1601 parliamentary elections. In 1568 he travelled to London to secure confirmation of Calne’s charter.
In 1604 Swaddon was elected to Parliament along with another clothier, John Noyes, probably in response to the king’s request for boroughs to return local men. He is not known to have spoken in the Commons. His solitary committee nomination, on 18 May, concerned a bill for the relief of parishes affected by plague, a problem relevant to Wiltshire at this date.
Contrary to expectations, Swaddon remained active in borough affairs until at least July 1606, and finally died in March 1607.
