Brothers in Law may refer to:

• Sibling-in-law, a person related to another by being the sibling of a spouse or the spouse of a sibling
• Brothers in Law (novel), a 1955 British novel
• Brothers in Law (film), a 1957 film adaptation
• Brothers in Law (TV series), a 1962 television series based on the novel
• Brothers in Law (Radio series) adapted from the TV series by Richard Waring
• The Brothers-in-Law, a Canadian musical group
• The Brother-in-Law, an 1817 play by Henry Card