Princess Emma of Waldeck and Pyrmont (2 August 1858 – 20 March 1934) was Queen of the Netherlands and Grand Duchess of Luxembourg as the wife of King-Grand Duke William III. An immensely popular member of the Dutch Royal Family, she also served as regent for her daughter, Queen Wilhelmina, during the latter’s minority.
Emma was born as Adelheid Emma Wilhelmina Theresia, Princess of Waldeck and Pyrmont on 2 August 1858 in Arolsen Castle in Arolsen, the capital of the small German principality of Waldeck and Pyrmont. She was the fourth daughter of Georg Viktor, Prince of Waldeck and Pyrmont and Princess Helena of Nassau.

Her brother, Friedrich, was the last reigning Prince of Waldeck and Pyrmont. Her sister, Helena Frederica, would become the wife of Prince Leopold, Duke of Albany, a son of Queen Victoria and Prince Albert.

Her maternal grandparents were William, Duke of Nassau and his second wife, Princess Pauline of Württemberg. Pauline was a daughter of Prince Paul of Württemberg and his wife Charlotte of Saxe-Hildburghausen.

Paul was a son of Frederick I of Württemberg and his wife, Duchess Augusta of Brunswick-Wolfenbüttel. Augusta was the eldest daughter of Karl Wilhelm Ferdinand, Duke of Brunswick-Luneburg and Princess Augusta of Great Britain, elder sister of George III of the United Kingdom.
Emma married the elderly King William III in Arolsen on 7 January 1879, two years after the death of his first wife, Princess Sophie of Württemberg. The aging, licentious King, once described as “the greatest debauchee of the age”, had previously been rejected by Emma’s sister Pauline and by Princess Thyra of Denmark.

With William, Emma had her only child, the future Queen Wilhelmina, on 31 August 1880. The King also had three sons from his first marriage, William, Maurice, and Alexander, all of whom died before him without any legitimate offspring.
Three days before William died on 23 November 1890, Emma became regent for her husband. She continued as regent for the new monarch, her underage daughter, Wilhelmina, the late King’s only surviving child until Wilhelmina’s eighteenth birthday on 31 August 1898. The Grand Duchy of Luxembourg, which could not be inherited by a woman at that time, passed to their distant cousin Adolf, Duke of Nassau who was also Queen Emma’s maternal uncle.

She was the 812th Dame of the Royal Order of Queen Maria Luisa.

She died in The Hague on 20 March 1934, of complications from bronchitis at the age of 75, and was buried in Delft.