Wú Rúyú 吳如愚 (1167–1244), zì Zǐfā 子發, hào Zhǔnzhāi 凖齋, was a Southern-Sòng Lǐxué recluse-classicist of Qiántáng 錢塘 (Hángzhōu). Inherited father’s Chéngxìn láng 承信郎 office; held minor revenue posts at Liánjiāng 連江 (Fúzhōu) and Chángshú 常熟; resigned and returned home. In Jiāxī 2 (1238) Chancellor Qiáo Xíngjiǎn 喬行簡 recommended him for Mìgé jiàokān 秘閣校勘; he memorialised three times to refuse, and was instead promoted to Bǐngyì láng 秉義郎 with a cí (sinecure) appointment. His career outline appears in the Guǎngé xùlù 館閣續錄 and Zhào Xībiàn 趙希弁’s Dúshū fù zhì; the Sòng shǐ gives him no biography. The most detailed primary source is Xú Yuánjié 徐元杰’s xíngzhuàng in his Méiyě jí 楳埜集. Major works: the Zhǔnzhāi zá shuō 凖齋雜說 (KR3a0066, partly recovered through the Yǒnglè dàdiǎn); a series of classical commentaries on the Yì, Shī, Shū, Dà xué, Zhōng yōng, Lúnyǔ, Mèngzǐ, plus an Yīnfú jīng jiě — all lost. CBDB id 35282, dates 1167–1244.