Ishikawa Chikayasu served as a bushō during the Sengoku period.

Chikayasu was a member of the Ishikawa clan based in Ogawa in the Hekikai District of Mikawa Province.  He was born as the third son of Ishikawa Masayasu and was the father of Ishikawa Tadasuke.  Chikayasu served Matsudaira Chikatada and Matsudaira Nagachika.

In 1446, his father, Masayasu, moved from Shimotsuke Province to the village of Shiki in the Hekikai District of Mikawa and built Ogawa Castle.  In 1471, Matsudaira Nobumitsu seized Anjō Castle from the Hatakeyama clan and installed his third son, Chikatada, as the lord of the castle.  Thereafter, Chikatada offered to engage one of Masayasu’s sons as a chief retainer and, upon orders of Masayasu, Chikayasu entered into service for Chikatada.  Chikayasu began this service at the age of fourteen and, the following year, attended his coming-of-age ceremony whereupon he received one of the characters from the name of Chikatada and adopted the name of Chikayasu.  Thereafter, he was charged with having the same character be passed on to later generations.

Chikayasu died on 9/12 of Kyōroku 3 (1530).