Genesee County Prosecutor David Leyton on Thursday charged the 32-year-old former Flint Northern High star with possession of a firearm in a sterile area of a commercial airport.
The misdemeanor carries a maximum sentence of a year in jail.
Leyton says Smith was going to take a flight to Atlanta in November when officials found a gun in his carry-on bag.
Smith's attorney, Frank Manley, tells The Flint Journal that Smith has been a role model for the community. Manley says the NFL has issued its own discipline of Smith.
Airport Director Jim Rice tells WJRT-TV Smith was questioned by airport police and "was very cordial, very apologetic."
The case is similar to that of Smith's teammate Shaun Rogers, who was arrested and charged with carrying a concealed weapon through security at Cleveland's Hopkins International Airport on April 1.
The 31-year-old nose tackle said he did not realize he had a loaded hand gun in his carry-on luggage when he was stopped. Rogers pleaded not guilty to the charge, which carries a maximum penalty of 18 months in prison.