| Honorific-Prefix: | Yang Berbahagia Datuk |
| Yong Khoon Seng | |
| Birth Name: | Yong Khoon Hian @ Yong Khoon Seng |
| Birth Date: | 22 December 1941 |
| Birth Place: | Betong, Sarawak |
| Office1: | Deputy Minister of Works |
| Term Start1: | 19 March 2008 |
| Term End1: | 15 May 2013 |
| Monarch1: | Mizan Zainal Abidin Abdul Halim |
| Primeminister1: | Abdullah Ahmad Badawi Najib Razak |
| Minister1: | Mohd Zin Mohamed Shaziman Abu Mansor |
| Constituency1: | Stampin |
| Office2: | Parliamentary Secretary of the Ministry of Works |
| Term Start2: | 1995 |
| Term End2: | 2008 |
| Monarch2: | Ja'afar Salahuddin Sirajuddin Mizan Zainal Abidin |
| Primeminister2: | Mahathir Mohamad Abdullah Ahmad Badawi |
| Minister2: | Samy Vellu |
| 1Blankname2: | Deputy Minister |
| 1Namedata2: | Railey Jeffrey Mohamed Khaled Nordin Mohd Zin Mohamed |
| Constituency2: | Padawan Stampin |
| Office3: | Parliamentary Secretary of the Ministry of National Unity and Community Development |
| Term Start3: | 1990 |
| Term End3: | 1995 |
| Monarch3: | Azlan Shah Ja'afar |
| Primeminister3: | Mahathir Mohamad |
| Minister3: | Napsiah Omar |
| 1Blankname3: | Deputy Minister |
| 1Namedata3: | Alexander Lee Yu Lung |
| Constituency3: | Padawan |
| Office9: | Faction represented in Dewan Rakyat |
| Subterm9: | 1990–2013 |
| Suboffice9: | Barisan Nasional |
| Party: | Sarawak United Peoples' Party (SUPP) |
| Otherparty: | Barisan Nasional (BN) |
| Occupation: | Politician |
| Profession: | Pharmacist |
| Alma Mater: | University of Queensland |
Datuk Yong Khoon Seng (; born 22 December 1941) was the Member of the Parliament of Malaysia for the Stampin constituency in Sarawak, representing the Sarawak United Peoples' Party (SUPP), from 1999 until 2013. He was a Deputy Minister of Works in the ruling Barisan Nasional coalition government.[1]
Yong entered Parliament in 1990 for the seat of Padawan. He was immediately appointed as a Parliamentary Secretary.[2] Before entering politics, he was a pharmacist, graduating from the University of Queensland.[3] He was born in Betong, Sarawak.[2]
However, at the 2013 general election, Yong lost his seat to a Democratic Action Party (DAP) candidate, Julian Tan Kok Ping.[4]
| Constituency | Candidate | Votes | Pct | Opponent(s) | Votes | Pct | Ballots cast | Majority | Turnout | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1990 | P158 Padawan, Sarawak | (SUPP) | 16,362 | 62.66% | Cheng Hui Hong (DAP) | 9,751 | 37.34% | 26,692 | 6,611 | 67.99% | ||||
| 1995 | P170 Padawan, Sarawak | (SUPP) | 19,258 | 72.33% | Akaw Nonjep (IND) | 7,368 | 27.67% | 27,867 | 11,890 | 88.09% | ||||
| 1999 | P170 Stampin, Sarawak | (SUPP) | 18,810 | 61.86% | Voon Lee Shan (DAP) | 9,913 | 32.60% | 31,098 | 8,897 | 60.91% | ||||
| Chua Chio Kuia (IND) | 1,684 | 5.54% | ||||||||||||
| 2004 | P196 Stampin, Sarawak | (SUPP) | 21,155 | 61.18% | Voon Lee Shan (DAP) | 13,424 | 38.82% | 35,806 | 7,731 | 59.87% | ||||
| 2008 | (SUPP) | 21,966 | 51.01% | Voon Lee Shan (DAP) | 18,896 | 43.88% | 43,922 | 3,070 | 65.30% | |||||
| See Chee How (PKR) | 2,198 | 5.10% | ||||||||||||
| 2013 | Yong Khoon Seng (SUPP) | 22,993 | 35.43% | (DAP) | 41,663 | 64.20% | 65,515 | 18,670 | 77.32% | |||||
| Soo Lina (STAR) | 239 | 0.37% | ||||||||||||