Yuiken 惟賢 (also read Igen; dates uncertain, fl. mid-14th century, c. 1320–1380) was a Tendai master of the Kurodani 黑谷 precept-revival lineage on Mt. Hiei and the abbot of Hosshō-ji 法勝寺 in Kyoto — the imperial temple where Echin (惠鎭) had also served. Yuiken received the distinctive Kurodani precept-consecration (kanjō-style esoteric initiation applied to bodhisattva-precept reception) at Seiryū-ji 青龍寺 in Kurodani on the 25th day of the 7th month of Jōwa 5 = September 1349, and afterward took it upon himself to document and defend the Kurodani ritual tradition against critics from other Tendai sub-schools.
His KR6t0081 Púsà yuándùn shòu jiè guàndǐng jì is a single-fascicle account of the Kurodani-lineage precept-kanjō procedure and a doctrinal-historical defence of its legitimacy. The work names the slanderers (without identifying their personal names) and traces the legitimate doctrinal lineage of the precept-kanjō tradition back to the earliest period of Buddhism.
Within the Kanripo corpus his preserved work is KR6t0081 Púsà yuándùn shòu jiè guàndǐng jì.
No CBDB record (Japan-only figure). No DILA Authority record currently locates him.