| Rank | Event | Year | Location | Result |
| Olympic Games |
| 5 | 100m Butterfly | 2008 | Beijing, CHN | 51.47 |
| Heats | 100m Freestyle | 2008 | Beijing, CHN | 49.06 |
| World Championships |
| 4 | 100m Butterfly | 2011 | Shanghai, CHN | 51.59 |
| 6 | 50m Butterfly | 2009 | Rome, ITA | 23.04 |
| 6 | 100m Butterfly | 2009 | Rome, ITA | 51.07 |
| 7 | 50m Butterfly | 2011 | Shanghai, CHN | 23.60 |
| Heats | 100m Freestyle | 2009 | Rome, ITA | 49.16 |
| World Championships Short Course |
| 7 | 100m Butterfly | 2010 | Dubai, UAE | 50.79 |
Hobbies
"Back in Kenya I love to spend time by the ocean surfing and fishing. I also have a passion for wildlife and ecology in which Kenya is so rich. I enjoy reading on various subjects as diverse as evolutionary biology, the world food economy and African history, as well as a good novel now and then [Stieg Larsson's Millennium trilogy being the most recent]." (Swimnews.swimfacts.com, 14 Oct 2010)
Occupation
Athlete
Education
Earth Sciences, Human Physiology - Stanford University, Stanford, CA, USA
Language(s) spoken
Swahili
Club name
Stanford University / ADN Swim Project, United States
Coach
Andrea Di Nino [club], Fahkry Mansoor [national] (Swimnews.com, 05 Oct 2011;Sportsnewsarena.com, 02 Aug 2011)
Other sports
His younger brother David is also a Kenyan international swimmer. (FINA Aquatics World Magazine, 15 Aug 2010)
Additional information
Start of sporting career
He began swimming competitively at the age of five at Kenton College primary school in Nairobi. (FINA Aquatics World Magazine, 15 Aug 2010)
Reason for taking up this sport
His father introduced him and his brothers to water sports off the coast of Mombasa. (FINA Aquatics World Magazine, 15 Aug 2010)
Ambitions
Winning a medal at the Olympic Games in 2012. "Given that I will be 25 when the Olympics come around in London, I suppose it could be my best and last chance to win a medal." He also wants to open a swimming academy in Kenya. "I have held swimming clinics back home, in Italy and the US, but opening an academy [in Kenya] would be my ultimate dream." (gulfnews.com, 13 Oct 2011; swimnews.swimfacts.com, 14 Oct 2010; en.beijing2008.cn, 20 Jul 2007)
Training
"I do five sessions of land work per week, three in the gym using weights, swim balls and medicine balls and two extra core workouts. Running, ergo rowing and cycling have also been a part of my training regime as well. In the off season I try to surf as much as possible and also play some golf and tennis. As a percentage of my overall work, ‘fly constitutes about 30-40 percent." (swimnews.swimfacts.com, 14 Oct 2010)
Most memorable sporting achievement
Winning gold medals at the 2006 African Championships in Senegal. "It was my greatest joy standing on the podium as the national anthem was being played," he said. "The feeling cannot be expressed in words and I am just happy to have put Kenya's name on the swimming map."
"Breaking the Olympic record in Beijing. Though I only held it for seven minutes, it caused a huge reaction in Kenya and surprised a lot of people."
(swimnews.swimfacts.com, 14 Oct 2010; Swim News, 26 Mar 2007)
Superstitions / Rituals
"Rituals are no longer really part of my world because I've realised that superstition counts for nothing other to distract me from the task at hand. I do breathing exercises to help me focus and reach a state of flow before my races. Also, on occasion staring at a singular point for a period of time can help me focus and better ‘get in the zone'." (swimnews.swimfacts.com, 14 Oct 2010)
Awards
He was named Overall Mens Swimmer of the Year at the 2011 All-Africa Games. (standardmedia.co.ke, 09 Nov 2011)
He was the first Kenyan to swim in an Olympic final in 2008 and was placed fifth. (swimnews.swimfacts.com, 14 Oct 2010)
He won the 2007 Safaricom Kenyan Sportsman of the Year Award. (sportykenya.com, 08 Nov 2010)
He was voted Kenya's Sportsman of the Year in 2007. (nation.co.ke, 04 Aug 2008)
He made history in the 100m butterfly at the 2006 African Championships in Senegal by winning Kenya's first major international swimming gold medal. (nation.co.ke, 04 Aug 2008)
General
ADN PROJECT
He represents the ADN (Andrea Di Nino) Swim Project which trains in Italy. "My national team and management are very supportive of me no matter where I decide to train. They realise it would be difficult to get the level of training I now require if I were to be based in Kenya. I have so far learned much being at ADN. Being a small group I get more individualised attention than is feasible on a collegiate swim team. I am also getting the chance to race in Europe." (swimnews.swimfacts.com, 14 Oct 2010)
FROM KENYA TO THE UK TO THE US
He was born in Kenya and first represented the country at the age of eight. He then moved to the United Kingdom to attend the Marlborough College in Wiltshire and captained the south west of England schools team in 2004. He moved to the United States to swim for Stanford University in the 2005/06 season. (gostanford.cstv.com, 10 Dec 2007; Swim News, 26 Mar 2007)
FAMILY
His father Martin Dunford is the chairman of the Tamarind Group which owns the Carnivore restaurant chain in Kenya. He is also the vice-chairman of the Kenya Swimming Federation and is a patron of the Nairobi Amateur Swimming Association [NASA]. His mother Geraldine Dunford is the granddaughter of Abraham Block, who founded Block Hotels. She is the company's marketing executive. Jason has an older brother who graduated from the London School of Economics and was captain of the rugby team. His younger brother David is a swimmer and represents Kenya.
(china.org.cn, 21 Jan 2012; sportykenya.com, 08 Nov 2010)
Previous Olympics
Beijing 2008
