Simpson entered the plea in a Kenton County, Ky., court in response to charges he trafficked marijuana in excess of 8 ounces -- a charge that could draw a sentence of one to five years in prison.
He was indicted Jan. 19 after a September arrest.
Prosecutors say police intercepted a package containing 2 1/2 pounds of marijuana shipped to Simpson's Kentucky home from California. A subsequent search of the home turned up another 6 pounds of pot, police allege.
Simpson's bond was set at $2,500. A hearing was scheduled for Feb. 20.