Captain Christian August Max Ahlmann Valentiner (December 15, 1883 – July 19, 1949) was a German U-boat commander during World War I.
He was the third highest-scoring U-boat commander of the war, and was awarded the Pour le Mérite for his achievements.
He was also listed as a war criminal by the Allies, for killing hundreds of civilians by sinking the passenger liner Persia without warning on December 30, 1915, contrary to international law.