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Ikeda Tomomasa (池田 知正; 1544 – 1603) was a kokujin and military commander in the Azuchi-Momoyama period. He was the second son of Ikeda Nagamasa, who was a dominant kokujin in Settsu Province. His older brother was Ikeda Katsumasa.
In 1568, when Oda Nobunaga marched his armies, Tomomasa and Katsumasa under Miyoshi clan battled against him. However, they were not equal to him by their nature. They surrendered and served Nobunaga. In 1570, when Ikeda clan's infighting happened, Katsumasa who was the family head was purged. Because of that, Tomomasa succeeded to a house. In 1571, he held secret communication with Miyoshi Nagayasu, Miyoshi Masayasu and Iwanari Tomomichi, and betrayed Nobunaga. They defeated Wada Koremasa and killed him.
However, Tomomasa surrendered again after Nobunaga ruled Settsu Province completely. He became a retainer of Araki Murashige. In 1580, he served Hashiba Hideyoshi after Murashige betrayed Nobunaga and was defeated. Tomomasa under Hideyoshi took part in the Battle of Komaki and Nagakute and the expedition to Kyūshū (in 1586).