Yóu Mào 尤袤 (1127–1194), zì Yánzhī 延之, hào Suìchū jūshì 遂初居士, posthumous name Wénjiǎn 文簡, was a Southern Sòng poet, official, and book collector from Wúxī 無錫. He took the jìnshì in Shàoxīng 18 (1148; not 1147 as sometimes stated) and rose through prefectural and metropolitan posts to lǐbù shàngshū 禮部尚書 (Minister of Rites). His Wúxī residence the Suìchūtáng 遂初堂 housed one of the largest private libraries of the Southern Sòng — Chén Zhènsūn 陳振孫 calls it “the foremost collection of recent times” (近世藏書之冠) — and his catalogue Suìchūtáng shūmù KR2n0003 is the earliest surviving Chinese bibliography to record alternative block-print editions of the same work (川本/吉州本/越州/湖北本 Hànshū etc.). Yáng Wànlǐ 楊萬里 wrote a preface (preserved in his Chéngzhāi jí 誠齋集) for what he called Yóu’s Yìzhāi shūmù 益齋書目 — Mǎ Duānlín cites the same preface for Suìchūtáng shūmù, indicating the two are the same catalogue under different names. Yóu was also one of the “Four Great Poets of Southern Sòng” (NánSòng sìdàjiā 南宋四大家) along with Yáng Wànlǐ, Lù Yóu 陸游, and Fàn Chéngdà 范成大, though most of his poetry is lost. Sòngshǐ j. 389 has his biography. CBDB 14856 confirms 1127–1194.