Father Petar "Pero" Brzica (born ca. 1917) was a Croatian Nazi collaborator and war criminal. Before the war he was a scholarship student at the Franciscan college of Široki Brijeg in Herzegovina and a member of The Great Brotherhood of Crusaders.
He spent some time studying law in Zagreb where he became the Ustashe Youth member and later a member of the Croatian fascist Ustaša government (1941-1945) and one of the guards in the Jasenovac concentration camp.
As an Ustashe he held the rank of Lieutenant.
While he is known for having beaten an inmate to death in March 1943, he is notorious for having won a contest in which he used a curve-bladed knife, also called a srbosjek, to kill newly-arrived concentration camp prisoners.
Brzica boasted of winning the contest by killing the largest number of prisoners - 1360 people. Some other sources set Brzica's "record" at a lower number, between 670 and 1100.