Peter (Church Slavonic: Петръ Bulgarian: Петър) (fl. 860s–870s) was a Bulgarian noble and relative of knyaz (khan) Boris I (r. 852–889) who was in charge of diplomatic missions during the Christianization of Bulgaria. His position in the Bulgarian administrative hierarchy is unknown but it has been suggested that he had the title kavhan, i. e. the second person in the state after the monarch.