Matthew Apperson, 27, also was found guilty of shooting into a vehicle and aggravated assault with a firearm, Michelle Kennedy, spokeswoman for the 18th Judicial Circuit, said.
A jury deliberated for four hours. Apperson will be sentenced October 17.
The charges stem from an incident in Lake Mary, Florida, in May 2015. Apperson had said it was a case of self-defense and Zimmerman had threatened to kill him.
Zimmerman testified that Apperson followed him, flashing his lights and honking his horn. Apperson pulled up beside Zimmerman and shot at him, but the bullet missed, Zimmerman said. Shattered window glass cut Zimmerman.
Zimmerman’s brother, Robert, tweeted: “Justice for George!”
Zimmerman became a controversial public figure in 2012 when he fatally shot teenager Trayvon Martin. The case prompted national debates about the use of firearms for self-defense and also racial issues. Zimmerman was acquitted of a second-degree murder charge in 2013.