Prosecutors in Delaware County, north of Columbus, said Friday the 63-year-old Stillwagon was indicted on four second-degree felony counts of felonious assault, all with firearm specifications. His arraignment is Monday.
Police said Stillwagon, who played at Ohio State, fired at the driver of a pickup truck Sept. 30. One of the shots grazed the 41-year-old man's head.
Stillwagon was legally carrying the gun, and his lawyer has said he fired in self-defence. A phone message left at the lawyer's home Friday was not immediately returned.
Stillwagon is a U.S. college Hall of Fame middle guard who helped the Buckeyes win a national championship in 1968.
A first-round pick of the NFL's Green Bay Packers in 1971, Stillwagon opted for Toronto and the CFL. He played five seasons with the Argos (1971-'75) and was a three-time league all-star.
On Sept. 11, 2009, Stillwagon was added to the Argos' all-time team.