Shinjitsu (years of birth and death unknown) was a monk at the end of the Heian period. His father was MINAMOTO no Yoriyasu of the Yamato Minamoto clan, whose go (pseudonym) was Hokkekyo Taro.
He successively held important posts in Kofuku-ji Temple, such as gon-jishu (vice-director of the temple), jishu (director of the temple), and joza (supervisor of the temple), and after the death of Kakujo, Betto (head priest of the temple), he assumed jimu (operation of the temple). Praised as 'the bravest armed monk in Japan,' he played a key role in Kofuku-ji Temple, which had gradually built up military forces to dispute MINAMOTO no Chikaharu of the same clan on the Yamato Province and to make an assault upon some temples on Mt. Kinpusen, leading many warrior monks of Kofuku-ji Temple in 1145.
His close relationship with FUJIWARA no Tadazane and his son Yorinaga led Shinjitsu to side with the Retired Emperor Sutoku's factions in the Hogen War in 1156. After Sutoku's defeat, the protection of Tadazene, who fled to Nanto (the City of Nara) with Tadazane's relatives Jinpan and Sengaku, provoked suspicions from the Chotei (the Imperial Court) to take up arms. For this reason, he had his estates forfeited by the Chotei just after the War, but in 1158, he was appointed Hokkyo (The third rank in the hierarchy of Buddhist priests), which proved that the Chotei still admitted his power.