Castlevania & History Special - Did You Know Gaming? Feat. Markiplier
There is a Yu-Gi-Oh! card called Vampire Hunter which is likely based off the Belmont family.
The Castlevania castle can be seen in the art's background and the card's name translated from Japanese is Vampire Killer, the name of a whip passed down through the Belmont family.
Contributed by Psychospacecow
The Entrance Hall area has almost exactly the same layout in most of the games in the series.
Contributed by ummwat
In Japan, the Belmonts are known as the Belmondos. Also, Trevor Belmont's name in Japan is Ralph C. Belmondo.
Contributed by peanutgamer
In the High Valryian language, from Game of Thrones, the word "Chain" is "Belmon". This is meant to be a reference to Simon Belmont from Castlevania, since he can get a chain whip.
Contributed by SRJ