Lord is a title with various meanings. It can denote a prince or a feudal superior (especially a feudal tenant who holds directly from the king, i.e., a baron). The title today is mostly used in connection with the peerage of the United Kingdom or its predecessor countries, although some users of the title do not themselves hold peerages, and use it 'by courtesy'. The title may also be used in conjunction with others to denote a superior holder of an otherwise generic title, in such combinations as "Lord Mayor" or "Lord Chief Justice". The title is primarily taken by men, while women will usually take the title 'lady'. However, this is not universal, as the Lord of Mann and female Lord Mayors are examples of women who are styled 'lord'.

In religious contexts Lord can also refer to various different gods or deities. The earliest uses of Lord in the English language in a religious context were by English Bible translators such as Bede. This reflected the Jewish practice of substituting the spoken Hebrew word 'Adonai' (which means 'My Lord') for YHWH when read aloud.

According to the Oxford Dictionary of English, the etymology of the word can be traced back to the Old English word 'hlāford' which originated from 'hlāfweard' meaning 'bread keeper' or 'loaf-ward', reflecting the Germanic tribal custom of a chieftain providing food for his followers. Lady, the female equivalent, originates from a similar structure, believed to have originally meant 'loaf-kneader'.