advice about ex's bills

What is the name of your state? IL

I need some advice. I was divorced 3 years ago and we were both supposed to pay our own bills. When going through my credit report I discovered that my ex-husband did not pay his credit card which he had put my name on (although I never used the card). In order to have this removed from my report I had to pay the bills in full. The total was almost $800. Can I take my ex to small claims court and recover the money? Also, I now live in another state. Would I have to return to IL, where we lived, to file this? Any advice from anyone here would be a big help.

Something is not correct in your post.....
You said that he "had put my name on (although I never used the card)."
Unless you signed the credit application agreeing to be liable.... there is simply no way that he could do as you claim. A party cannot add or transfer liability to another without that persons agreement. However, since someone managed to 'sucker' you into paying his debt, your lack of liability is no longer relevant.

"In order to have this removed from my report I had to pay the bills in full. The total was almost $800. Can I take my ex to small claims court and recover the money?"
*** Of course you can file a lawsuit against him as anyone can sue almost anyone over almost anything. The problem you will have is in trying to convince the court that you were OBLIGATED (see above) to pay... and that by paying, he is now obligated to you. The family court order may help.... and it is likely you might win... but it is not a clear issue.

"Also, I now live in another state. Would I have to return to IL, where we lived, to file this?"
*** It is far more practical (and maybe required due to jurisdictional issues) that you pursue the claim in his state.