岳母一般是指妻子的母亲（自己则为女婿），相对岳父（妻子的父亲）而言。也有称为泰水，对应岳父的别称泰山。通俗的称呼还有“丈母娘”。

在不少作品里，岳母往往被描绘成麻烦、过度维护女儿而刁难女婿；若是入赘女婿，岳母更常常当着家中众人奚落女婿。现实生活中虽然也不乏以上例子，但也有很多岳母与女婿相处融洽。

俗语常说「丈母娘看女婿，越看越满意。」

A parent-in-law is a person who has a legal affinity with another by being the parent of the other's spouse. Many cultures and legal systems impose duties and responsibilities on persons connected by this relationship. A person is a son-in-law or daughter-in-law to the parents of the spouse, who are in turn also the parents of those sisters-in-law and brothers-in-law (if any) who are siblings of the spouse (as opposed to spouses of siblings). Together the members of this family affinity group are called the in-laws.