It popped up out of nowhere. Any help appreciated
Thanks!
SOLVED: SOLVED: Is this a weed?
That is a Platanus occidentalis - American Sycamore - seedling. Seeds will drift in on the wind, and germinate in unexpected places.
Sycamore is a big full sized canopy shade tree, so probably not growing where you want to keep it. It would not be difficult to transplant, or pot up and give away to someone who may need/want it.
Thanks for solving!
You are quite welcome.