妻姊妹婚，是指男子同时以两个或多个姊妹为配偶，或者在妻子去世后续娶其姊妹的行为或习俗。此在一夫多妻制社会中经常出现。

中国最早记载的妻姊妹婚为舜帝同时娶尧的二女娥皇、女英为妃。春秋、战国时代的诸侯婚姻经常为姐妹同嫁一夫。如《尔雅·释亲》载“女子同出，谓先生为姒，后生为娣。”，郭璞注“同出谓俱嫁事一夫”。后来又变化成以同姓宗女（侄娣）陪嫁，称为媵。后世比较著名的姊妹同嫁一夫包括：赵飞燕与赵合德、大周后与小周后。清朝后宫中为姐妹关系的有孝庄文皇后和敏惠恭和元妃、孝惠章皇后和淑惠妃、珍妃与瑾妃等。

景颇族有妻子死后男子续娶其未婚姊妹的风俗。北美洲的纳瓦约族印第安人传统的一夫多妻婚姻中，也经常有同时娶姐妹的。

Sororate marriage is a type of marriage in which a husband engages in marriage or sexual relations with the sister of his wife, usually after the death of his wife or if his wife has proven infertile.

From an anthropological standpoint, this type of marriage strengthens the ties between both groups (the wife's family or clan and the husband's) and preserves the contract between the two to provide children and continue the alliance.