Onakatomi no Sadanaga (大中臣定長)
ONAKATOMI no Sadanaga (date of birth unknown - January 3, 1143) was a waka (a traditional Japanese poem of thirty-one syllables) poet who lived in the latter part of the Heian period. He was a son of ONAKATOMI no Sadanobu (大中臣定登) and was adopted as a son of ONAKATOMI no Kinnaga who was his uncle (the youngest brother of his father) and Junii saishu (Junior Second Rank, chief priest). His son was ONAKATOMI no Kiyonaga.
Since his adopted father Kinnaga was stopped from his duties because of an accusation of murder in 1138, Sadanaga was implicated in it and was stopped from shinji gubu (to be in attendance on divine services). After that, he was transferred to the Gon no taifu (vice-minister of Jingikan, department of worship) and died on January 3, 1143. One of his waka was selected for "Kinyo Wakashu" (Kinyo Collection of Japanese poems) (song number 672).