Langstrothdale is a scenic valley in the Yorkshire Dales in North Yorkshire, England. The uppermost course of the River Wharfe runs through it, but Wharfedale does not begin until the Wharfe meets Cray Gill, downstream of Hubberholme. The name Langstrothdale derives from Old English and translates as 'long marsh' or 'marshy ground'.

The Yorkshire Dales are a series of valleys, or dales, in the Pennines, an upland range in England. They are mostly located in the ceremonial county of North Yorkshire, but extend into Cumbria and Lancashire; they were historically entirely within Yorkshire. The majority of the dales are within the Yorkshire Dales National Park, created in 1954. The exception is the area around Nidderdale, which forms the separate Nidderdale Area of Outstanding Natural Beauty.