Petar Mrkonjić (circa 17th century) was a Croatian hajduk from Imotski Krajina.
Little is known about Mrkonjić, except that he was active during the Cretan War (1645–1669) between the Venetian Republic and Ottoman Empire, and has been documented as Petar Imoćanin (Petar, the man from Imotski). Today, he is the subject of numerous Croatian patriotic songs, many noted by the Croatian friar and poet Andrija Kačić Miošić in the 18th century.