Seo Jung-jin
South Korean businessman; co-founder and chairman of the Celltrion group
| Seo Jung-jin
| |
|---|---|
| Born | 23 October 1957 (Forbes) |
| Nationality | South Korean |
| Residence | Seoul (Forbes) |
| Occupation | Businessman |
| Known for | Co-founder and chairman of Celltrion |
| Education | Konkuk University (Forbes) |
Seo Jung-jin (born 23 October 1957) is a South Korean businessman, co-founder and chairman of the biopharmaceutical group Celltrion, which is best known for biosimilar drugs.[1] Forbes says he returned as group chairman in 2023, two years after stepping down.[1] Later that year Celltrion merged with its sales affiliate Celltrion Healthcare, and in 2025 it bought an Eli Lilly plant in New Jersey.[2][3] On 11 November 2026 the Forbes Real-Time Billionaires list ranked Seo 371st in the world, with an estimated net worth of US$9.7 billion; Forbes lists the source of wealth as biotech.[1][4] In the annual World's Billionaires list published in 2026, Forbes had ranked Seo 346th, at US$9.9 billion.[5]
Early career
Forbes says Seo worked for Samsung Electro-Mechanics and for Daewoo Motor, the conglomerate that went bankrupt in the Asian financial crisis of the late 1990s.[1]
Celltrion
Forbes says Seo started Celltrion in 2002 and listed it in 2008. Its drugs treat conditions including cancer, influenza and rheumatoid arthritis, and in partnership with Teva it won FDA approval for Herzuma, a biosimilar breast cancer treatment.[1] He stepped down as group chairman in March 2021, and Forbes says he returned in 2023 promising major acquisitions.[1] His eldest son, Seo Jin-seok, co-chairs Celltrion Inc.[1]
Merger with Celltrion Healthcare
On 28 December 2023 Celltrion said it had completed its merger with Celltrion Healthcare, which shareholders had approved in October.[2] The new structure put Seo Jin-seok, then chairman of Celltrion's board, in charge of general management.[2] Korea Biomedical Review reported that Celltrion Holdings, chaired by Seo Jung-jin, had previously controlled the two companies separately and would become the largest shareholder of the combined company with 21.5%. A further merger with Celltrion Pharm was planned for 2024.[6]
US manufacturing
In September 2025 Celltrion said its US unit had bought ImClone Systems, the Eli Lilly subsidiary that runs a manufacturing plant in Branchburg, New Jersey, for US$330 million. The Korea Times described the purchase as a move to protect the company from proposed US tariffs on pharmaceuticals.[3] At a press conference Seo said Celltrion would spend 1.4 trillion won (about US$1 billion) in total on buying, running and expanding the plant.[3]
Wealth history
Forbes has included this entry in its annual World's Billionaires list in 14 of the editions from 2001 to 2026 checked for this profile, starting with 2013. The table gives the rank and estimated net worth in each annual list.[5][1]
| Year | World's Billionaires rank | Net worth (US$ bn) |
|---|---|---|
| 2013 | 1175 | 1.2 |
| 2014 | 1565 | 1.0 |
| 2015 | 1533 | 1.2 |
| 2016 | 959 | 1.9 |
| 2017 | 939 | 2.2 |
| 2018 | 126 | 11.9 |
| 2019 | 181 | 8.1 |
| 2020 | 253 | 6.1 |
| 2021 | 145 | 14.2 |
| 2022 | 343 | 7.0 |
| 2023 | 455 | 5.6 |
| 2024 | 364 | 7.3 |
| 2025 | 464 | 7.1 |
| 2026 | 346 | 9.9 |
International and political links
This section uses the same ten headings for every profile in this series. Only specific, sourced actions are included; company-level and foundation-level actions are labelled as such. Where nothing was found, the entry reads "No documented involvement found in sources checked."
Israel (investments, operations, donations, contracts, statements)
No documented involvement found in sources checked.
Zionist or pro-Israel organisations and lobbying groups
No documented involvement found in sources checked.
Jewish communal charities
No documented involvement found in sources checked.
Gulf states
No documented involvement found in sources checked.
China
No documented involvement found in sources checked.
Russia
No documented involvement found in sources checked.
India
No documented involvement found in sources checked.
Palestinian or Arab causes
No documented involvement found in sources checked.
Home government
Seo lives in Seoul. Celltrion is listed in South Korea.[1][6]
Other international links
In 2025 Celltrion bought a manufacturing plant in New Jersey, in the United States.[3]
Notes
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Forbes, Forbes profile record for Seo Jung-jin (Forbes data feed behind forbes.com/profile/seo-jung-jin/) Forbes, live record, read 11 November 2026, accessed 11 November 2026.
- ↑ 2.0 2.1 2.2 Yonhap News Agency, Celltrion completes merger with sales unit as part of integration plan Yonhap News Agency, 28 December 2023, accessed 11 November 2026.
- ↑ 3.0 3.1 3.2 3.3 Nam Hyun-woo, Celltrion acquires Eli Lilly bio plant in New Jersey The Korea Times, 23 September 2025, accessed 11 November 2026.
- ↑ Forbes, Forbes Real-Time Billionaires data feed Forbes, live; downloaded 11 November 2026 16:19 UTC, accessed 11 November 2026.
- ↑ 5.0 5.1 Forbes, Forbes World's Billionaires list data feed, annual editions 2001–2026 (one file per year at this path with the year substituted; all 26 files downloaded and read) Forbes, annual lists; downloaded 20 October 2026, accessed 11 November 2026.
- ↑ 6.0 6.1 Korea Biomedical Review, Celltrion starts anew after its merger with Celltrion Healthcare Korea Biomedical Review, 28 December 2023, accessed 11 November 2026.