A State Bureau of Investigation (SBI) is a state-level detective agency. They are plainclothes agencies which usually investigate both criminal and civil cases involving the state and/or multiple jurisdictions. They also provide technical support to local agencies in the form of laboratory or record services.

In Germany, the state bureau of investigation are called Landeskriminalamt.

In the United States of America, it is the state's equivalent to the Federal Bureau of Investigation. The SBIs investigate all manner of cases assigned to them by their state's laws and usually report to the State's Attorney General, and in some cases to the state's Governor.