Irthlingborough is a town on the River Nene in North Northamptonshire, England. It had a population of 8,900 at the 2011 Census. It is an ancient settlement, with evidence of pre-historic and Roman occupation.
Irthlingborough is known for its history, archaeology, independent shops, and nature. The parish church, St Peter, has a lantern tower, unusual for Northamptonshire churches, which was built to guide travellers across the Nene valley in foggy weather. It also has doors at the four cardinal points and has eight misericords in the chancel.
Irthlingborough Lakes and Meadows is a nature reserve that has been created from former gravel quarries. The reserve is home to a variety of wildlife, including birds, mammals, and insects. There are also several walking and cycling trails around the lakes.