《寂寞之井》，又译《孤寂深渊》（英语：The Well of Loneliness）是1928年英国作家瑞克里芙·霍尔所着的女同性恋小说。故事描述出身上流家庭的英格兰女子史提芬·戈登，自幼便表现出她的「反性别行为」（即同性恋）。她在一次大战担任救护车司机时，结识并爱上了玛莉·卢埃林，但却遭到社会孤立、排斥。小说中史提芬的「反性别行为」是天生、与生俱来的，霍尔并为此明确恳切的表示道：「也给我们生存的权利。」

《寂寞之井》成了一连串风潮中的众矢之的，《周日快报》编辑詹姆士·道格拉斯评论道：「我宁可给健康男孩或女孩一瓶氰化氢，也不会让他们接触这本小说。」而小说中仅有的一幕性爱情节只含蓄写道「而那晚，她们未被分割」，却被英国法院以「妇女间的反常行为」罪名，断定猥亵。在美国，《寂寞之井》的合法性亦受纽约州与海关法庭质疑，但最后并未遭禁。

The Well of Loneliness is a 1928 lesbian novel by the British author Radclyffe Hall. It follows the life of Stephen Gordon, an Englishwoman from an upper-class family whose "sexual inversion" (homosexuality) is apparent from an early age. She finds love with Mary Llewellyn, whom she meets while serving as an ambulance driver in World War I, but their happiness together is marred by social isolation and rejection, which Hall depicts as having a debilitating effect on inverts. The novel portrays inversion as a natural, God-given state and makes an explicit plea: "Give us also the right to our existence".