Nishio Tadayoshi (西尾 忠善, September 2, 1768 – January 30, 1831) was a daimyō in mid-Edo period Japan, who ruled Yokosuka Domain in Tōtōmi Province.
Nishio Tadayoshi was the fourth son of Makino Sadanaga, daimyō of Kasama Domain in Hitachi Province.
Tadayoshi also revised fishing laws and encouraged sword production for the purpose of stabilizing the domain's finances.
In 1829, citing illness, Tadayoshi resigned from his position as daimyō, yielding it to his fourth son, Tadakata.
His grave is located at the Nishio clan temple of Ryumin-ji in modern Kakegawa, Shizuoka.