In the Irish Census 1901, there was 4,680 people listed with the name Hurley in Ireland. 141 listed with the name Hurly.
310 Hurley in Co. Kerry. 39 Hurly.
3,042 Hurley in Co. Cork.
171 Hurley in Co. Limerick.
194 Hurley in Co. Clare.
In the Irish Census 1911, 4,544 people listed with the name Hurley in Ireland. 92 listed with the name Hurly.
337 Hurley in Co. Kerry. 12 Hurly.
2,884 Hurley in Co. Cork.
220 Hurley in Co. Limerick.
170 Hurley in Co. Clare.
If you are searching for a Hurley/Hurly ancestor, you can clearly see here that the concentration of the name is in Co. Cork. However if you know that your Hurley/Hurly ancestor comes from Kerry, Limerick or Clare the field narrows considerably!
My grandmother spelled her name Hurley but in the 1901 Census her father and her grandfather are listed as Hurly. By 1911, her family name is recorded in the Census as Hurley. This demonstrates how important it is to know variants of the surname that you are searching.