HRH, an abbreviation of His/Her Royal Highness, is used as part of the title of some members of the royal family. Her title was styled as HRH The Duchess of Sussex. What is an "HRH" title? The letters stand for His or Her Royal Highness, a style used to denote senior members of the royal family. ROYAL titles are awarded by the Queen to members of her family, but only some members of the Royal Family hold the prestigious title of His. HRH is a reference to either His or Her Royal Highness. HRH stands for Her Royal Highness.