Maple Tree Disease
That is tar spot, a foliar disease on maples caused by a fungus. You might say it looks kind of ugly, but it's usually not a big concern for overall tree health. Please see the following articles:
Why do my maple leaves have spots?! from MSU Extension
When to control tar spots on Maples from MSU Extension
Tar Spot of Maple from Cornell University
It's probably not necessary for this issue, but if you ever have other tree health concerns, especially where you are considering treatment, think about contacting a local International Society of Arboriculture (ISA)-certified arborist at https://www.treesaregood.org/findanarborist . There should be an ISA-certified arborist at work in your general area. If no one comes up in your initial search, try searching a nearby city or zip code.
Also, consider managing for general tree health, such as watering during times of drought stress.
Please let me know if you have further questions!