康瓦尔郡（英语：Cornwall，国际音标：/'kɔrnwɒl/；康沃尔语：Kernow；香港旧译歌和老），大不列颠岛西南端的半岛，英国英格兰西南端的区。康瓦尔东与德文郡相邻，南临英伦海峡，西、北临大西洋。以人口计算，特鲁罗是最大城市（亦是行政总部），圣奥斯特尔是第一大镇（Town）。

2009年之前，康瓦尔是34个非都市郡之一，实际管辖6个非都市区，占地3547平方公里（第9），人口为524200（第23）；如看待成48个名誉郡之一，它名义上包含多1个单一管理区——锡利群岛，占地增至3563平方公里（第12），人口增至526,300（第39）。

Cornwall (/ˈkɔːrnwɔːl/ or /ˈkɔːrnwəl/; Cornish:Kernow, [ˈkɛɹnɔʊ]) is a ceremonial county and unitary authority area of England within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of 536,000 and covers an area of 3,563 km (1,376 sq mi). The administrative centre, and only city in Cornwall, is Truro, although the town of Falmouth has the largest population for a civil parish and the conurbation of Camborne, Pool and Redruth has the highest total population.