Harwell is a hamlet in the civil parish of Everton, in Bassetlaw district, northern Nottinghamshire, England.

The hamlet had a population of 112 people in the mid 19th century and the Corporation of Newark were lords of the manor at that time.

Today, the main feature of Harwell is the Grade II listed Pear Tree House and the Barrow Hills woodland, immediately to the northwest.

Selected extracts from the Domesbook mentioning Harwell are as follows:[3] "In Evretone and Hereuuelle of the fee of Roger de Busli in Oswardebec Wapentac, soc to Burton, there was two bov.

The jury, found that John Freschevede held in the town of Herewell, one bovat of land in demesne, seven natives (or villains) holding five bov.

[4] The parish of Everton, in which Harwell is located, was inclosed in 1760, when the Rectorial tithes were commuted for an allotment of 225 acres, of which William Walton, Esq., of Stockwith, was impropriator at the time.

[4] The manor was previously owned by Thomas Magnus who bought it and gave it to Anthony Gylby who was Lieutenant Colonel to Sr John Digby in Newark.

[8] Harwell is located in the broad, low-lying River Idle valley of central Nottinghamshire.