In-law (disambiguation)

In-law may refer to:
 * Affinity (law), kinship by marriage, such as:
 * Parent-in-law, a mother-in-law or father-in-law
 * Sibling-in-law, a sister-in-law or brother-in-law
 * In-law apartment, a type of secondary residence
 * In-Laws, an 2002-2003 American situation comedy that aired on NBC
 * The In-Laws (1979 film), an American action-comedy film starring Alan Arkin and Peter Falk
 * The In-Laws (2003 film), an American comedy film starring Michael Douglas and Albert Brooks
 * The In-Laws (2021 film), a Polish comedy film
 * The In-Laws 2, a 2023 Polish comedy film