The 18th century saw the architect James Paine commissioned by John Burdon in 1754 to design and construct a Palladian estate at nearby Hardwick Hall. The building work was never completed as Burdon went bankrupt, but sufficient landscaping was done to form the basis of the now renovated Hardwick Hall Country Park.
The 19th century South African politician and industrialist Henry Barrington was born in Sedgefield and actions by his offsprings indirectly lead to the South African town Sedgefield, Western Cape being named in honour of his birthplace.
In the 19th century, Sedgefield was a great hunting centre, dubbed 'the Melton of the North'. Hunter Ralph Lambton had his headquarters at Sedgefield: the humorous writer, Robert Smith Surtees, who lived at Hamsterley Hall, was a friend of his. On 23 February 1815, Lord Darlington wrote: 'Mr Ralph Lambton was out with some gentlemen from Sedgefield, and a most immense field.'
Sedgefield was also known in the area because of Winterton Hospital. This was an isolation hospital and an asylum. The site was like a village itself with its own fire station, bank and cricket team. Today, little trace is left of the hospital, apart from the church, which is now surrounded by the Winterton housing estate and the NETPark Science park.