Yōgon 永嚴 (1075–1151) was a senior Japanese Shingon master of the late Heian period, of the Daigo-ji Sanbō-in 醍醐寺三寶院 transmission line — the principal Daigo-affiliated branch of the broader Ono-ryū 小野流. He was a senior disciple of Shōkaku 勝覺 (1057–1129), the founder of Sanbō-in as a sub-temple of Daigo-ji (1115), and rose to the Sanbō-in Sōjō rank. His ritual notebooks — the KR6t0184 Yàozūn fǎ (one fascicle, surviving), together with the now-lost or partially surviving Seven-Fascicle Compendium 七卷抄 and Ten-Fascicle Compendium 十卷抄 — were the principal practical reference works of the Sanbō-in transmission for over a century.
Yōgon also served as religious counselor to the cloistered emperor’s circle and as a senior officiant at imperial-prayer rituals. He held the rank of daisōjō by the end of his life.
Surviving work in the Kanripo corpus: KR6t0184 Yàozūn fǎ (1 fasc.).