No official constellation has a name that begins with the letter W. The International Astronomical Union recognizes 88 constellations that divide the entire sky, and not a single one of them starts with this letter. This gap stands out because the list covers nearly every other letter of the alphabet, from Andromeda to Vulpecula, yet the letter W is left empty.

The reason for this absence comes from history and language. Most constellation names trace back to Latin, and they describe figures from ancient Greek and Roman mythology, such as heroes, animals, and everyday objects. The Latin alphabet that astronomers use did not treat W as a standard letter, since the sound was usually written with a V or a U. Because the names were set centuries ago and follow these older spelling rules, no formal constellation ever received a name opening with W.

A few patterns come close enough to be worth noting. The constellation Cassiopeia is famous for its bright stars that form a clear W shape in the night sky, which is one of the easiest patterns for beginners to find. Some people also think of informal star groups, called asterisms, that carry W-related nicknames, though these are not counted among the 88 official constellations. For anyone looking for a true constellation that starts with W, the simplest answer is that one does not exist.