The House of Hanover (German: Haus Hannover), whose members are known as Hanoverians, is a European royal house of German origin that ruled Hanover, Great Britain, and Ireland at various times during the 17th to 20th centuries. The house originated in 1635 as a cadet branch of the House of Brunswick-Lüneburg, growing in prestige until Hanover became an Electorate in 1692. George I became the first Hanoverian monarch of Great Britain and Ireland in 1714. At Queen Victoria's death in 1901, the throne of the United Kingdom passed to her eldest son Edward VII, a member of the House of Saxe-Coburg and Gotha. The last reigning members of the House of Hanover lost the Duchy of Brunswick in 1918 when Germany became a republic.

The formal name of the house was the House of Brunswick-Lüneburg, Hanover line. The senior line of Brunswick-Lüneburg, which ruled Brunswick-Wolfenbüttel, became extinct in 1884. The House of Hanover is now the only surviving branch of the House of Welf, which is the senior branch of the House of Este. The current head of the House of Hanover is Ernst August, Prince of Hanover.