Lady Otsuya

Otsuya no Kata おつやの方
Castellan of Iwamura castle (De facto Toyama clan head)
Incumbent
Assumed office 1572
Preceded by	Tōyama Kagetō
Personal details
Died	December 1575
Spouse(s)	Tōyama Kagetō Akiyama Nobutomo
Relatives	Oda Nobunaga (nephew) Oichi (niece)
Military service
Allegiance	Oda clan Takeda clan
Unit	Toyama clan
Battles/wars	Siege of Iwamura castle

Lady Otsuya (おつやの方 Otsuya no Kata) was a Japanese female samurai (onna-musha) from the Sengoku period. She was the ruler of Iwamura Castle until the last days of her life.

According to legend Otsuya is best known for the aunt of the famous samurai Oda Nobunaga, the wife of Tōyama Kagetō and foster mother of Oda Katsunaga. She also having conspired against the Oda clan and fought against her nephew, Oda Nobunaga. Her execution under Nobunaga may have been one of the reasons for the decline in Nobunaga's reputation, who would later be murdered by Akechi Mitsuhide and others traitors in the Incident of Honnoji.