Yukawa Tan 湯川倓 (sinicized Tāngchuān Dàn), zì An-dào 安道, fl. late 18th to early 19th century, Edo Japan. Younger brother of 丹波元簡 (Tamba no Mototane, 1755–1810), the head of the bakufu’s Igaku-kan 醫學館. The principal documentary trace of Yukawa Tan is his postface (bá) of Kyōwa guǐhài (= 1803, 1st lunar month, 9th day) to his brother’s Jiùjí xuǎnfāng 救急選方 (KR3ed098). In the postface he describes himself as Mototane’s húdì 胞弟 (uterine younger brother) and as a fellow Igaku-kan-affiliated scholar of the Chinese medical canon. No further biographical record is available in the standard Edo medical reference works; he is presumed to have predeceased his brother.