Merpeople are sentient beings that live underwater, and are found all over the world. Their customs and habits are mysterious, and, like the Centaurs, they refused Being status in favour of Beast. Merpeople can breathe above the waves for a time, but it is unclear if they can ever truly leave their habitat.

Merpeople society is based around organised communities, and they have a great love of music. Their language is known as Mermish, and only a few Wizards know how to speak it. However, since their language can only be heard properly underwater, it sounds like screeching when spoken above water.

Merpeople have been known to keep Grindylows as pets, and use Lobalugs as weapons. One tribe even managed to capture and domesticate a Hippocampus.

The term "Merpeople" is an umbrella term. There are several distinct sub-species around the world. Sirens are the earliest recorded Merpeople, and are often depicted in Muggle literature and paintings as beautiful. The Selkies of Scotland, and the Merrows of Ireland, are less pleasing to the eye. However, despite their physical differences, they all retain their love of music.