The structure standing today, roughly 65 metres long and most likely built by the Shannon Navigation in the 1840s as part of the extensive programme to manage and improve Ireland's inland waterways, occupies a crossing point that was already old when Victorian engineers arrived.

The earliest reference to a bridge here comes from 1595, when Hugh Roe O'Donnell, the Gaelic chieftain from Donegal whose campaigns against Elizabethan rule made him one of the period's central figures, crossed at Knockvicar into County Roscommon. The crossing is noted in both the Ordnance Survey Letters and the Annals of the Four Masters, the great seventeenth-century chronicle of Irish history compiled by Franciscan scholars, which suggests the moment was considered significant enough to record rather than simply pass over. Whether the structure O'Donnell used was a proper bridge or something more makeshift is not entirely clear, but the place itself was evidently a recognised and usable ford or crossing. A later bridge is documented by the writer Isaac Weld, who noted in 1832 that one had been constructed on the site in 1728, meaning the present structure is in fact at least the third iteration of a crossing that has served this stretch of the river for well over four hundred years.