What stands today is a nineteenth-century structure, considerably altered from earlier forms, yet the site it occupies has functioned as a crossing point since at least the early eleventh century, when a plank bridge here was already in use during the lifetime of Brian Boru, the High King of Ireland who died at the Battle of Clontarf in 1014.

The crossing kept changing hands, and sometimes disappearing altogether. In 1071 the Irish king Toirdelbach Ua Briain built a bridge at this location, a structure the Annals of Innisfallen records as having been completed in a fortnight, presumably in timber. That same bridge, or a successor, was destroyed by Hugh O'Donnell in 1599 during the Nine Years' War, and the site reverted to a ford. A Parliamentary officer's diary from the mid-seventeenth century mentions the ford but makes no mention of any bridge, suggesting the crossing had not been rebuilt. By 1654 to 1656, however, the Civil Survey describes a bridge here spanning the Shannon to Killaloe. Whether it lasted is uncertain; Herman Moll's map of 1714 shows only a ferry at the site, which suggests the bridge had gone again, or was never more than a temporary structure. By 1778 it appears once more, drawn on Taylor and Skinner's road map of Ireland. The bridge as documented in a plan of 1837 was a substantial crossing of fifteen segmental arches, with five central arches each spanning 40 feet (12 metres) and the remainder averaging 20 feet (6 metres). The roadway between the stone parapet walls was 18 feet (5.5 metres) wide, and the triangular cutwaters, the projecting piers designed to deflect the river's current, were mostly capped with semi-pyramidal stonework. Eleven of those cutwaters were raised to parapet level to create pedestrian refuges, small alcoves where a person on foot could step clear of passing traffic on the narrow roadway.