Remington Orr, 24, who worked as a custody assistant at the Men's Central Jail, faces several felony charges.
Investigators say he had been under surveillance and that he was arrested on Monday as he tried to enter the jail to distribute drugs.
Sheriff's spokesman Steve Whitmore said Orr will be prosecuted to the fullest extent of the law.
Orr is being held on $1 million bail.
Recently, three sheriff's guards have been convicted on charges they smuggled or tried to smuggle narcotics into jail for inmates.