Early-Joseon civil official and scholar who took part in creating Hunminjeongeum

| Life | 1396 ~ 1478 |
| Era | 조선 |
| Clan | 하동 정씨 |
Jeong In-ji, styled Baekjeo and known by the pen name Hakyeokjae with the posthumous title Munseong, served from the reigns of King Taejong through Seongjong, rising from Chancellor of the Hall of Worthies and Minister of Personnel to second and then chief state councillor.
Under King Sejong he took part in creating Hangul as a Hall of Worthies scholar, writing the preface to the Hunminjeongeum Haerye, and made major contributions to astronomy and calendrical science, including the Yongbieocheonga and the calendrical treatise Chiljeongsan naepyeon. With Kim Jong-seo he oversaw the compilation of the History of Goryeo and its companion digest, organizing the historical record of the Goryeo dynasty. He supported the Gyeyu coup and King Sejo's enthronement, earning merit-subject status, and became doubly linked to the royal house when his daughter-in-law was Sejo's daughter and his grandson married a daughter of Sejo's son Prince Deokwon.
In his later years he was impeached, while drunk, for criticizing Sejo over the killing of the deposed King Danjong and for favoring Buddhism, but Sejo pardoned the outburst as drunken indiscretion. He is buried in Oeryeong-ri, Buljeong-myeon, Goesan County, North Chungcheong Province, a site designated Chungcheongbuk-do Monument No. 33, and left behind the collected writings Hakyeokjaejip.
His grave is located in Oeryeong-ri, Buljeong-myeon, Goesan County, North Chungcheong Province.