What is the name of the floating cloud city in Equestria?

The floating cloud city in Equestria is Cloudsdale.

Cloudsdale is the largest known settlement of the pegasi in My Little Pony: Friendship Is Magic. The city floats on clouds and moves through the sky, making it visually distinct from ground-based locations such as Ponyville, Manehattan, and Canterlot. It is closely associated with weather production and aerial culture.

The Rainbow Weather Factory is located in Cloudsdale, where clouds, snow, rainbows, and other weather effects are prepared for distribution across Equestria. The city is also the home associated with Rainbow Dash and Fluttershy during their early years, and it hosts major flying events, including the Best Young Flyer competition.

Cloudsdale’s clouds normally support only pegasi. Earth ponies and unicorns can fall through them unless a spell grants them the ability to walk on clouds. That rule explains several comic scenes in which non-pegasi visitors need magical help to move around the city.

The name is also a horse-related pun: “Cloudsdale” echoes Clydesdale, the breed of draft horse. It should not be confused with Las Pegasus, another floating location that appears later in the series.