I am a male with a circle like rash on the top inside of my thighs near the crease in my skin. That keeps coming back, what could it be?

Circle rash on thigh. Although there are a few other things that this could be the most likely is a fungal rash. Usually it will respond to an over the counter antifungal cream but may need to treat it for several weeks, and keep the area as dry as possible.