Grandson of Seo Hui; chief councillor under King Seonjong with the rank of Sangjuguk
| Era | 고려 중기 |
| Clan | 이천 서씨 |
Seo Jeong was a mid-Goryeo official of the Icheon Seo clan and a grandson of Seo Hui. His dates are unknown. His career begins in 1065 (King Munjong) when, as Jeonjung-sogam, he went to the Khitan as envoy, and in 1089 (King Seonjong) he was appointed Samsa-sa.
He later served as Minister of War and Jungchuwon-sa. In 1092 he went out as military commander of the northwest and the central army, and in June of that year became Chamji-jeongsa. In 1093 he became Sangseo-jwabogya and, via Pansamsa-sa, Jungseo-sirang Pyeongjangsa with the rank of Sangjuguk. The northwest bordered the Khitan, so Seo Hui's frontier experience seems to have passed to his grandson.
He is counted as the fourth of the chief ministers after Seo Pil, Seo Hui and Seo Nul. His posthumous title and tomb were not confirmed.
Namuwiki's article gives the line Seo Sin-il, Seo Pil, Seo Hui, Seo Yu-geol, Seo Jeong, Seo Gyun, Seo Gong, while noting that sources disagree whether Seo Yu-geol was Seo Hui's son (per epitaphs) or Seo Nul's brother (per genealogy). Seo Jeong's father may therefore be given differently by source.
Father-son links of Goryeo figures often differ between epitaphs and genealogies, so descendants should check their own genealogy.
Not confirmed in sources
His grandfather was Seo Hui, and genealogies run Seo Jeong, Seo Gyun, Seo Gong. See also the Icheon Seo clan page.