A queen dowager or dowager queen (compare: princess dowager or dowager princess) is a title or status generally held by the widow of a king. In the case of the widow of an emperor, the title of empress dowager is used. Its full meaning is clear from the two words from which it is composed: queen indicates someone who served as queen consort (i.e. wife of a king), while dowager indicates a woman continues to hold the title from her deceased husband (a queen who reigns in her own right is a queen regnant). A queen mother is a former queen consort, often a dowager queen, who is the mother of the reigning monarch.

Currently (2019) there are four queens dowager: Kesang Choden of Bhutan (who is the only living queen grandmother worldwide), Norodom Monineath of Cambodia (who is also queen mother), Lisa Najeeb Halaby (Noor Al'Hussein) of Jordan, and Sirikit Kitiyakara of Thailand (who is also queen mother). Queen Ratna of Nepal was queen dowager until the abolition of the Nepalese monarchy in 2008.