How many viking languages are there?

There's no such thing as "Viking languages". The term "Viking" refers to a period of Scandinavian history (roughly 8th to 11th centuries), not a distinct group of languages.

During the Viking Age, people from Scandinavia spoke Old Norse, a language that evolved into the modern Scandinavian languages:

* Danish

* Swedish

* Norwegian

* Icelandic

* Faroese

Therefore, there's no set number of "Viking languages" since it refers to a historical period and not a linguistic group.