I guess the answer depends entirely what toilet your RV is using but the answer is probably no. Thetford is the manufacturer of most RV toilets and they are typically smaller and probably shaped differently than a home style toilet.
You could simply take your RV toilet seat in and compare it at Wal-Mart or leave it in your truck, go in and buy a replacement, carry the new one out and compare it with the original, and return it if it doesn't fit.