Formal:
* Je vous verrai mercredi. (I will see you Wednesday.)
* Je vous retrouverai mercredi. (I will meet you Wednesday.)
Informal:
* On se voit mercredi. (We'll see each other Wednesday.)
* À mercredi! (See you Wednesday!)
More Specific:
* Je te verrai mercredi après-midi. (I'll see you Wednesday afternoon.)
* On se retrouve mercredi matin. (We'll meet Wednesday morning.)
Note:
* "On se voit" is a very common and informal way to say "see you" in French.
* "À mercredi" is a short and casual way to say "see you Wednesday."
* You can use "vous" (formal) or "tu" (informal) depending on the person you are talking to.
Choose the phrase that best suits the situation and your relationship with the person.