Imperial and Royal Highness (abbreviation HI&RH) is a style possessed by someone who either through birth or marriage holds two individual styles, Imperial Highness and Royal Highness. His/Her Imperial Highness is a style used by members of an imperial family to denote imperial – as opposed to royal – status to show that the holder is descended from an Emperor rather than a King or Queen. Holders of the style Imperial Highness generally rank above holders of the style Royal Highness.

A primary example of the contemporary usage of this style is the Belgian Royal Family. HI&RH Lorenz, Archduke of Austria-Este, Prince of Belgium is a member of the Imperial House of Habsburg-Lorraine by birth, but upon his marriage to HRH Princess Astrid of Belgium, he also became a member of the Belgian Royal Family by marriage. As such, their children currently use the styles HI&RH as members of both the Royal family of Belgium and the Imperial House of Habsburg-Lorraine.