How do you spell oops I spelled that wrong in French?

There isn't a direct equivalent to "oops, I spelled that wrong" in French. However, you could express it in a few ways, depending on the context:

Formal:

* "Oh, je me suis trompé(e) en orthographiant cela." (Oh, I made a mistake in spelling that.)

* "Pardon, j'ai fait une erreur d'orthographe." (Excuse me, I made a spelling error.)

Informal:

* "Oups, j'ai fait une faute d'orthographe." (Oops, I made a spelling mistake.)

* "Zut, j'ai mal orthographié ça." (Darn, I spelled that wrong.)

* "J'ai buggé !" (I messed up!)

The best option will depend on the situation and who you are speaking to.