Ikeda Nagamasa (池田 長正; 1519 – June 10, 1563) was a kokujin and samurai commander during the Sengoku period. Ikeda Katsumasa and Ikeda Tomomasa were his sons.
His father was Ikeda Nobumasa and his mother was Miyoshi Masanaga's daughter, both dominant kokujin. In 1548, Nobumasa betrayed Hosokawa Harumoto. He was defeated, and as a result was forced to commit suicide. Nagamasa succeeded to headship of the house on his father's death, ruling the whole of Settsu Province. He became a retainer of Miyoshi Nagayoshi following his defeat at Nagayoshi's hands. He subsequently fought against Yasumi Naomasa as a retainer of the Miyoshi clan.
Nagamasa died on June 10, 1563 and was succeeded by his eldest son Ikeda Katsumasa.