The Royal Guelphic Order (German: Königlicher Guelphen-Orden), sometimes referred to as the Hanoverian Guelphic Order, is a Hanoverian order of chivalry instituted on 28 April 1815 by the Prince Regent (later King George IV).^[1] It takes its name from the House of Guelph, of which the Hanoverians were a branch. Since Hanover and the United Kingdom shared a monarch until 1837, the order was frequently bestowed upon British subjects.^[2]

Until 1837 the order was frequently awarded to officers in the British Navy and Army,^[3] although it was still classed as a foreign order, with British members of the order not entitled to style themselves as "Sir" unless they were also created Knights Bachelor, as many were.^[4]

The British link ended in 1837 when Hanover's royal union with Great Britain ended, with Ernest Augustus becoming King of Hanover and Queen Victoria ascending the British throne.^[2] When Hanover was annexed by the Kingdom of Prussia in 1866, the order continued as a house order to be awarded by the Royal House of Hanover. Today, its current Sovereign is the Hanoverian head of the house, Ernst August, Prince of Hanover.^{[citation needed]}

The insignia was based on the white horse on Hanover's arms.^{[citation needed]}

The Order includes two divisions, Civil and Military, the latter indicated by crossed swords on both the badge and star.^[3] It originally had three classes, but with several reorganisations since 1841, as house order today it has four classes and an additional Cross of Merit. In descending order of seniority the classes are:

• Hanoverian Waterloo Medal
• Order of Ernst August
• Order of St. George (Hanover)