Leathley is a parish in the Harrogate district of North Yorkshire near its southern border with West Yorkshire. The church of St Oswald stands on a small hill above meadows of the River Washburn, about a mile above its confluence with the Wharfe. It has a magnificent strong tower described as 'Early Norman' by Pevsner. Nave, aisles, and chancel later. Chancel arch of 12th c., but virtually no Romanesque sculpture is present.

Lawton (1842), p. 88, says the church was given to Nostell Priory; no date given. Lawton also says the original patron saint is unknown.

Pevsner writes that window opening into the nave must have been exterior because it is otherwise "useless". If so, the nave W wall would be slightly earlier than the tower. However, the splay may have made it easier for someone in the tower to see the interior of the church, in which case they would be contemporary.

The ironwork on the door below this window may be the former exterior door as it is said the woodwork is more weathered on the face than the rear (Leach and Pevsner 2009, 389).