Guō Zhōngxiào 郭忠孝 (d. 1127, Jìngkāng 2), zì Lìzhī 立之, hào Jiānshān 兼山先生, of Hénán 河南 / Luòyáng 洛陽. A direct pupil of 程頤 Chéng Yí for over two decades and a Chéng-school Yì-master in the xiàngshù-leaning branch — sometimes counted as a fifth alongside the canonical Chéngmén sì xiānshēng 程門四先生 (楊時 Yáng Shí, 游酢 Yóu Zuò, 謝良佐 Xiè Liángzuǒ, 呂大臨 Lǚ Dàlín).
Held office to Yǒngxīngjūn lù tíxíng 永興軍路提刑 (provincial judicial commissioner of Yǒngxīngjūn) under Huīzōng and Qīnzōng. At the Jìngkāng catastrophe (1126–1127) refused to surrender Yǒngxīngjūn to the Jin and died in the defense of the city.
His principal scholarly work, the Jiānshān Yì jiě 兼山易解, was substantively complete before his death but was scattered in the chaos of the Jin invasion. His son 郭雍 Guō Yōng (1091–1187) reconstructed and extended the family-Yì doctrine as the Guō shì chuánjiā Yì shuō 郭氏傳家易說 (KR1a0033) over the next sixty years in mountain retreat at Xiázhōu’s Chángyáng valley.
The Sòngshǐ (juan 448) places him in the Zhōng yì zhuàn 忠義傳 (“Loyalty-and-Righteousness Biographies”).