Tobin is not an indigenous Irish name, but the family can be regarded as having become completely hibernicized. Its Irish form, Toibín, is a gaelicized version of the Norman ‘St. Aubyn.’ Another interpretation is that the name was first called de St. Aubyn and the original bearers were from Aubyn, in Brittany, France.
According to the renowned Irish historian and genealogist, Edward MacLysaght (1887-1986), the family came to Ireland in the wake of the Norman invasion and by 1200 were settled in Counties Tipperary and Kilkenny, from where they spread to the neighboring counties of Waterford and Cork. They are still found in considerable numbers in those counties, though the name is relatively rare elsewhere in Ireland. The Tobins became so influential in Co. Tipperary that in medieval times, the head of the family was known as Baron of Coursey, though this was not an officially recognized title. According to Clyn in his annals, the fourteenth century Tobins were a turbulent sept more dreaded by the English settlers than the native Irish. The place Ballytobin near Callan, Co. Kilkenny took its name from them.