Yes. There are three "official" .NET languages: C#, Visual Basic, and F#.

https://dotnet.microsoft.com/en-us/languages

Wow... I keep forgetting that VB.net is still a thing. Pretty much everyone who was writing ASP code before the switchover adopted VB.net and then flipped over to C# around 2005 (.NET version 2).

It’s a shame the “Iron” family of scripting language implementations seem to have stalled out.

IronPython and IronRuby had a lot of potential.

RIP J#

RIP Midori

Yes, they also released F# 9.

Argh, my client omitted a wink smiley I've included at the end . It was meant as a joke.

Did you mean "are there other things called C# besides the language?" I think people missed the joke because they interpreted your comment as "are there other .NET languages?"