山小屋指的是山中建造的可供借宿、休息、避难的建筑。又可分为有人管理的有人小屋与无人的避难小屋而广义的山小屋还包括了农林业人员在山中兴建的小屋。此外，还有登山客利用自然洞窟寄宿，被称作「岩小屋」「岩室」。在欧洲、北美等地，山小屋较为普遍，特别是登山观光游客多的阿尔卑斯山脉、洛基山脉等。山小屋也被登山人称作「山中的旅馆」。

A mountain hut (also known as alpine hut, mountain shelter, mountain refuge, mountain lodge, and mountain hostel) is a building located high in the mountains, generally accessible only by foot, intended to provide food and shelter to mountaineers, climbers and hikers. Mountain huts are usually operated by an Alpine Club or some organisation dedicated to hiking or mountain recreation.