Ikoma Chikamasa (生駒 親正 1526 – March 25, 1603) was a Japanese daimyō during the Azuchi-Momoyama and Edo periods around the turn of the 17th century. His father was Ikoma Chikashige. Chikamasa was appointed one of the three chūrō (arbiters) by Toyotomi Hideyoshi.
In 1566, he became a retainer of Oda Nobunaga when he attacked Mino Province. He worked under Hashiba Hideyoshi (Toyotomi Hideyoshi) from then on, and was involved in various battles such as the Battle of Nagashino, the battle against Ishiyama Hongan-ji and the battle against the Saika party at Kii Province. In 1582, he served Hideyoshi after Nobunaga died, and was active in several battles such as the Battle of Yamazaki, the Battle of Shizugatake, the Siege of Odawara, and the Battle of Bunroku. He was given lands in Sanuki Province yielding 171,800 koku of rice because of his service. In Hideyoshi's last years, Ikoma Chikamasa, Nakamura Kazuuji, and Horio Yoshiharu were appointed to the position of chūrō under Toyotomi.
In 1600 at the Battle of Sekigahara, Chikamasa was part of Ishida Mitsunari's force while his son, Ikoma Kazumasa was part of Tokugawa Ieyasu's force. Chikamasa remained at Sanuki and sent his retainers in his stead to attack Tanabe castle in Tango Province. He chose this strategy to preserve the Ikoma clan regardless of which side prevailed. Because Kazumasa fought in Ieyasu's force, Ieyasu allowed Chikamasa to rule his existing domain after the battle, but Chikamasa took responsibility for fighting on the losing side by transferring the headship of the family to Kazumasa. He became a priest and withdrew to Mount Kōya.
| Daimyō of Takamatsu