Mother-in-law is a kinship relationship as a result of marriage.

Mother-in-law may also refer to:

• "Mother-in-Law" (song), a 1961 song recorded by Ernie K-Doe
• Mother-in-law (sandwich), a fast food dish of Chicago
• Mother-in-Law (TV series), a Kenyan comedy-drama series
• Mother-in-Law Island, in Connecticut, U.S.
• The Mother-in-Law, a 1734 play by James Miller
• The Mothers-in-Law, an American TV show premiering in 1967

See also

• Mother-in-law apartment
• Mother-in-law language
• Mother-in-Law Lounge