Duchess Louise of Mecklenburg-Strelitz (Luise Auguste Wilhelmine Amalie; 10 March 1776 – 19 July 1810) was Queen of Prussia as the wife of King Frederick William III. The couple's happy, though short-lived, marriage produced nine children, including the future monarchs Frederick William IV of Prussia and German Emperor Wilhelm I.

Her legacy became cemented after her extraordinary 1807 meeting with French Emperor Napoleon I at Tilsit – she met with the emperor to plead unsuccessfully for favorable terms after Prussia's disastrous losses in the Napoleonic Wars. She was already well loved by her subjects, but her meeting with Napoleon led Louise to become revered as "the soul of national virtue". Her early death at the age of thirty-four "preserved her youth in the memory of posterity", and caused Napoleon to reportedly remark that the king "has lost his best minister". The Order of Louise was founded by her grieving husband four years later as a female counterpart to the Iron Cross. In the 1920s conservative German women founded the Queen Louise League, and Louise herself would be used in Nazi propaganda as an example of the ideal German woman.