Allendale , often marked on maps as Allendale Town , is a village and civil parish in south west Northumberland , England. At the 2001 census, the parish had a population of 2,120,  decreasing to 2,021 at the 2011 Census.  Allendale is within the North Pennines Area of Outstanding Natural Beauty  (AONB) – the second largest of the 40 AONBs in England and Wales. The local economy is predominantly based on agriculture (notably sheep farming) and tourism, although of late it has become a popular commuter town for Newcastle upon Tyne.
Allendale refers to the "dale" or valley of the River Allen. Evidence of prehistoric settlement has been found on the surrounding moorland. In the 16th century this area, close to the Scottish border, was a lawless and troubled place. Fortified farmhouses known as ' bastles ' were constructed to protect residents and livestock against reiver raids. Allendale has one of the greatest concentrations of bastles in the country and around 40 can still be seen, many as scenic ruins.
Local mining for lead has occurred since Roman times, with the first smelting mill being constructed in the 1600s. The significant growth of Allendale Town and the surrounding villages was fuelled by that of the local lead-mining and smelting industries in the nineteenth century. The remains of two flues from the former smelting mill (between Allendale and Catton) run to chimneys up on the fells high above the village. The smelting mill is now home to the Allendale Brewery  and the Allenmills Regeneration Project.