Lady Chaa (茶阿局 Chaa no Tsubone) (? – July 30, 1621) was a concubine of Tokugawa Ieyasu, the founder of the Tokugawa shogunate in Japan. She lived in Tōtōmi Province.
When the daikan (a local official) had her husband killed, she appealed to Ieyasu, who was then the lord of Hamamatsu Castle; as a result, he punished the daikan.
She subsequently became a concubine of Ieyasu, and in 1592 bore him a son Matsudaira Tadateru.
Chaa died in 1621. Her grave is at Sōkei-ji, a Buddhist temple in Bunkyō, Tokyo.