Actors/Actresses:
* Rhea Perlman (Actress known for her role as Carla Tortelli on "Cheers")
* Rhys Ifans (Welsh actor known for roles in films like "Notting Hill" and "Spider-Man")
* Rupert Grint (Actor known for his role as Ron Weasley in the "Harry Potter" series)
* Rachel Hurd-Wood (British actress known for roles in films like "Peter Pan" and "Solomon Kane")
* Richard Harris (Irish actor known for his roles in films like "Camelot" and "Harry Potter and the Sorcerer's Stone")
Musicians:
* R. Kelly (Singer and songwriter)
* Rihanna (Singer and songwriter)
* Richard Harris (Irish actor and singer)
* Robert Hunter (Lyricist for the Grateful Dead)
Other:
* Richard Branson (British entrepreneur and founder of Virgin Group)
* Rachel Hunter (New Zealand model)
* Rupert Murdoch (Australian media mogul)
It's important to note that this is not an exhaustive list, and there are likely many other famous individuals with the initials RH. It's also possible that you were thinking of a specific person, and the initials are simply a coincidence.
Would you like me to try to narrow down the possibilities based on any additional information you have? For example, what is their profession or what type of celebrity are you looking for?