Nidderdale is one of the Yorkshire Dales (although outside the Yorkshire Dales National Park) in North Yorkshire, England. It is the upper valley of the River Nidd, which flows south through the dale, forming several reservoirs including the Gouthwaite Reservoir, before turning east and eventually joining the River Ouse.

The only town in the dale is Pateley Bridge. Other settlements include Wath, Ramsgill, Lofthouse, and Middlesmoor above Pateley Bridge, and Bewerley, Glasshouses, Summerbridge, Hampsthwaite, Birstwith, Darley, Kettlesing and Felliscliffe below Pateley.

Nidderdale was designated an Area of Outstanding Natural Beauty in 1994. In addition to Nidderdale itself (above Hampsthwaite), the AONB includes part of lower Wharfedale, the Washburn valley and part of lower Wensleydale, including Jervaulx Abbey and the side valleys west of the River Ure.

Nidderdale was historically in the West Riding of Yorkshire. Since 1974 it has fallen within the Borough of Harrogate in North Yorkshire.