Tai Si (Chinese: 太姒, c. 12th – 11th century BC) was the wife of King Wen of Zhou and is revered as a highly respected woman of ancient China.

Particularly respected by Wu Zetian, China's only Empress regnant, Tai Si and King Wen were posthumously given the temple names "Shizu" (Chinese: 始祖; lit.

[2] The traditional story regarding Tai Si's rise to queen says that the future King Wen of Zhou, born Chang, was walking along the banks of the Wei River one day when he first met Tai Si.

Tai Si proved a woman of benevolence, wisdom, and simple tastes, and Chang decided to take her as his wife.

Guan ju, the famous opening song of the Book of Songs, with its opening description of a beautiful maiden plucking plants along a river bank who is loved by a young prince, is said by some to be originally about Tai Si and the prince's first meeting along the Wei River.