Mark Chay Jung Jun (simplified Chinese: 蔡荣俊; born 18 February 1982) is a Singaporean freestyle swimmer who has represented the Republic in, amongst others, the SEA Games and Summer Olympics. His international swimming career began at the 1997 SEA Games, and stretched all the way till the 2005 SEA Games. In between, he has competed in a total of five SEA Games, two Asian Games, two Commonwealth Games and two Olympics.
He has been awarded "Singapore Sportsboy of the Year" in 2000, and Sportsman of the Year in 2001. Chay competed and studied at Brigham Young University in Provo, Utah. He was the Mountain West Conference Champion. Chay graduated from Brigham Young University with a degree in Communications: Communications studies emphasis. Chay retired from swimming in July 2007.
On 14 January 2021, Chay was chosen as one of the 9 Nominated Members of Parliament (NMP) for the 14th Parliament of Singapore, which began on 21 January 2021. After his appointment was announced, Chay said that he intends to speak on sports as an agent of social change and a way to unify a nation, prompted by the impact of the COVID-19 pandemic on Singapore's sports scene. In addition, Chay plans to speak on economic issues too.
- Abdullah, Zhaki (14 January 2021). "Nine new Nominated Members of Parliament to be appointed". CNA. Retrieved 19 January 2021.
- Singh, Dilenjit (19 January 2021). "Ex-Olympic swimmer Mark Chay wears many hats, his latest as NMP". The New Paper. Retrieved 19 January 2021.
- Abdul Aziz, Sazali (19 January 2021). "#GameOfTwoHalves Podcast: NMP Mark Chay on plans to help local sport survive beyond Covid-19". The Straits Times. Retrieved 19 January 2021.
- Singapore Swimming Association: Records at the Wayback Machine (archived 2007-03-17)
- Mark Chay at Olympics at Sports-Reference.com (archived)