Yes.

Did you plant sunroots?

No, but the birds might have?

It does look like a helianthus for sure, though.

May I ask, what's the source of your garden soil? Was it the existing soil or did you buy/import/obtain some and from where?
Knowing the source may help narrow down the ID for the seeds in the soil.

Example: I imported some compost from a friend's yard and it contained Pokeweed, crab grass, and other weeds, but it also gave me plenty of Four O'clocks, Cosmos and Zinnia plants.

Your plants (and weeds) look very healthy.

I use a no-till system. I have a very diverse garden. I make my own compost. Last spring I did get some from the county though. I have a large wild garden in the front of my house. There are many rain gardens in our neighborhood. I mulched last fall with shredded leaves from a neighbor.