There are several actors who appear in both the Game of Thrones and Lord of the Rings franchises, lending their talents to the two biggest titles in fantasy media. Peter Jackson's Lord of the Rings movies predate the popularity of Game of Thrones by over a decade, and it made sense for HBO to target actors from recognizable fantasy and historical fiction titles when developing their series. For example, Lena Headey was best known for her role in 300, Peter Dinklage appeared in The Chronicles of Narnia, and Sean Bean famously played Boromir in Lord of the Rings.

In the aftermath of Game of Thrones and the original Lord of the Rings trilogy, both franchises have expanded with prequel spinoffs. House of the Dragon and The Rings of Power have continued the trend of casting actors from the opposite franchise. After all, finding actors for period dramas is incredibly difficult,...