The Vikings named it Waesfjord (meaning 'harbour of mud flats') and its handy location near the mouth of the River Slaney encouraged landings as early as AD 850. The town was captured by the Normans in 1169; traces of their fort can still be seen in the grounds of the Irish National Heritage Park.
Cromwell included Wexford in his destructive Irish tour of 1649–50. Around 1500 of the town's then 2000 inhabitants were killed, including all the Franciscan friars. During the 1798 Rising, rebels made a determined, bloody stand here before being defeated.