Kirby Underdale is a village and civil parish in the East Riding of Yorkshire, England. It is situated approximately north of Pocklington town centre and lies north of the main A166 road from York to Driffield.
The civil parish is formed by the village of Kirby Underdale and the hamlets of Garrowby, Painsthorpe and Uncleby. According to the 2011 UK census, Kirby Underdale parish had a population of 125, a decrease on the 2001 UK census figure of 129.
The parish originally covered an area of over 5,000 acres, but in 1935 almost two-thirds of its area was transferred to the neighbouring parish of Thixendale.
In 1974 most of what had been the East Riding of Yorkshire was joined with the northern part of Lincolnshire to became a new English county named Humberside. The urban and rural districts of the former counties were abolished and Humberside was divided into non-metropolitan districts. The new organization did not meet with the pleasure of the local citizenry and Humberside was wound up in 1996. The area north of the River Humber was separated into two "unitary authorities"—Kingston-upon-Hull covering the former City of Hull and its closest environs, and the less urban section which, once again, named itself the East Riding of Yorkshire.