Brownlee was educated at
Bradford Grammar School before attending the
University of Leeds, where he studied history. He swam for Aireborough Swimming club and still holds the record for the A&W boys 9/10 yrs 2 lengths backstroke, which was set in 2000. He is a member of the Bingley Harriers and is coached by Malcolm Brown and Jack Maitland at the
British Triathlon Federation's High Performance Centre, based at
Leeds Metropolitan University's Carnegie Centre. Jonny is the joint record holder (with his brother Alistair) for most wins in the Chevin Chase with 5 wins - Jonny won the Chevin Chase in 2010, 2011, 2012, 2013, and 2016. His father Keith was a runner, while his mother Cathy was a swimmer. His older brother
Alistair Brownlee holds two Olympic titles in the triathlon event (2012, 2016), and is a two-time Triathlon World Champion (2009, 2011). His younger brother Edward is also a keen sportsman, but prefers rugby and water polo over the triathlon. Brownlee was the British youth champion in both the triathlon and duathlon in 2006 and 2007. In 2008, he won bronze medals at both the ETU European Junior Triathlon Championships and
ITU World Junior Championships, and placed 17th in his ITU World Championship Series début event in
Kitzbühel. During the 2009 season, he also won gold in the triathlon at the
Australian Youth Olympic Festival and competed in two races in the
2009 ITU World Championship Series, finishing 13th in
Kitzbühel and 27th in
London. Despite a 15-second penalty, Jonathan took the bronze medal in
the Triathlon event at the
London 2012 Olympic Games, his brother Alistair taking gold. He took gold in the mixed triathlon team relay at the 2014 Commonwealth Games, with his brother Alistair,
Vicky Holland and
Jodie Stimpson. At the
2020 Summer Olympics in
Tokyo, Brownlee took the second-leg of the inaugural
triathlon mixed relay, with
Jessica Learmonth,
Georgia Taylor-Brown and
Alex Yee, and took the gold medal in a time of 1:23:41. Brownlee also finished 3rd in the 2021
Super League Triathlon Championship Series. ==ITU competitions==