In European property law, Jure uxoris (Latin for "by right of (his) wife" is a title of nobility held by a man because his wife holds it suo jure ("in her own right"). Similarly, the husband of an heiress could become the legal possessor of her lands. In England until the Married Women's Property Act 1882, married women were legally incapable of owning real estate.

Jure uxoris monarchs are not to be confused with kings consort, who were merely consorts of their wives, not co-rulers.

Currently in Spain, the husband of a peeress in her own right may use his wife's title socially, although he is not technically entitled to it under the law. For example, Jaime de Marichalar was often referred to as the Duke of Lugo during his marriage to Infanta Elena, Duchess of Lugo. After their divorce, he ceased to use the title. His brother-in-law Iñaki Urdangarin was referred to as the Duke of Palma before corruption allegations prompted the King to take action. Since June 12, 2015 he is no longer referred to as the Duke of Palma de Mallorca, following the removal of that title from his wife, the Infanta Cristina.