Marie Louise Gonzaga (Italian: Maria Luisa, Polish: Ludwika Maria, Lithuanian: Liudvika Marija; 18 August 1611 – 10 May 1667) was Queen of Poland and Grand Duchess of Lithuania by marriage to two kings of Poland and grand dukes of Lithuania, brothers Władysław IV and John II Casimir. Together with Bona Sforza (1494–1557), she is regarded as one of the most influential and powerful queen consorts of the Kingdom of Poland and the Polish–Lithuanian Commonwealth.
Born in Nevers to Charles I, Duke of Mantua and Catherine of Guise, Marie was brought up at the French court as the future bride of Duke Gaston of Orléans. In 1645, she married Władysław IV of Poland with whom she did not have a harmonious relationship. After his death in 1648, the widowed queen married his half-brother and successor, John II Casimir. Marie Louise exercised considerable influence over her second husband and dictated the political course in the country. An ambitious and energetic woman, she was a strong supporter of an absolute monarchy for which she was reviled by certain spheres of the Polish szlachta and Lithuanian nobility. She, nevertheless, remained active in the Commonwealth's politics and co-sponsored the foundation of the first Polish newspaper, Merkuriusz Polski Ordynaryjny (Polish Mercury Ordinary), in 1661 as well as other public institutions.