district, administrative county of North Yorkshire, northern England, historic county of Yorkshire, England. It includes part of the Cleveland Hills, whose southern extension is known as the Hambleton Hills, from which the district takes its name. The hills form the west-facing escarpment of the North York Moors, which rise to more than 1,000 feet (305 metres) and flank the fertile lowland corridor—10 to 15 miles (16 to 24 km) wide—of the Vales of Mowbray and York. This sheltered lowland of clay soils is rich agricultural land, with numerous villages and small market towns. Northallerton, the largest town, is the administrative centre of the district.

After the partial colonization of the clay country by Anglian and Danish farmers, much was periodically laid waste in succeeding centuries by the Normans and later by the Scots. With agricultural improvements in the 18th century, Northallerton, Thirsk, Bedale, and Easingwold all became prosperous market towns, but they failed to grow much in the 19th century.

The eastern hills, which are now part of the North York Moors National Park, have villages settled in Anglian times that now attract tourists. Stokesley, the only old Cleveland market town in Hambleton district, is a residential suburb of neighbouring Middlesbrough. Increasing mechanization of agriculture has displaced many farmworkers, and alternative employment in light industry exists mainly at Northallerton and Thirsk, both situated near the improved road link with the Teesside towns and the north. Area 506 square miles (1,312 square km). Pop. (2001) 84,123.