"Thailand next week. I don't have my divorce papers with me. My question is, when filling out the pre-marriage affidavit at the U.S. Embassy, can I say that I am single and not divorced?"

I would not do that, if I was you. Lies are no good, if they find out. Why didn't you take the divorce papers with you, if you planed to get married in Thailand? 

Please reconsider your pending marriage for a while. There is no rush. Don't let her pressure you. We all just can't wait to fall in love with the first skirt that gives us a boyfriend kiss. Go slow, take your time. Stay together for five years and then marry her,he is still around. Thailand and Thai marriage is not for everyone. Failure rate high as the USA and just as expensive to end. I am on year five with my unmarried Thai wife and all is well. Remember one quote from a friend. "Honey, I not your girlfriend anymore, I your wife" You can add your own interpretation of that.

good luck and drive slooow

bella

I don't recall the OP asking whether or not he should get hitched ......

But he asked if he should lie!