Jack Sinclair (born 28 September 1992 in New Town, Tasmania) was the youngest person ever (at 15 yo) to cycle across Australia until 2013 when Daniel Mallinson made the journey at 10 years old. He completed the 4,500 kilometre ride from Cottesloe Beach, Perth in Western Australia to the beach of Surfers Paradise, Queensland in just 30 days (11 September 2008 to 10 October 2008).
Sinclair rode to raise funds ($25,000) for the youth mentoring charity Big Brothers Big Sisters of Australia. He was accompanied on the ride by his father, Brendon Sinclair. Professional cyclist Robbie McEwen was the Ride Ambassador  and provided training and ride advice.
His interest in endurance cycling commenced when he donated a web site to charity bike ride "Sydney to Surfers"  - a site he continues to manage - that raises in excess of $200,000 per year for the Youth Off The Streets charity.
In July 2009, Sinclair completed the 42.2 kilometre Gold Coast Airport Marathon. Two weeks later he completed the 96 kilometre Kokoda Challenge bushwalk. Sinclair is also a regular competitor in the Noosa Triathlon, an Olympic distance triathlon and a pilot (currently training for his private pilot's license).
In a four- (4) week period from 4 July 2010, Sinclair ran the Gold Coast Half Marathon, the Brisbane Half Marathon and was a member of the record breaking winning school team  for the grueling 96 km Kokoda Challenge.
On 27 April 2011 (at the age of 18 years), Sinclair completed a solo 1,200 km run around Tasmania in 27 days to raise money for charity.
Sinclair is a leading Scout, having been awarded the Australian Scouting Medallion  in 2008.
He continues ongoing fundraising for Big Brothers Big Sisters and helps increase awareness by giving speeches to Scouting groups on the importance of doing your best and helping others.
In November 2009 Sinclair was named as the youngest finalist in the Young Australian of the Year Awards (Queensland).
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- Courier Mail, News Corp.
- Big Brothers Big Sisters of Australia News Update Big Brothers Big Sisters of Australia News
- Robbie McEwen Ride Ambassador Letter
- Sydney to Surfers Official Web Site
- http://www.kokodachallenge.com/past-results Kokoda Challenge Results
- Hobart Mercury - Finally Time For Knees Up
- Palm Beach Scouts Award Announcement
- Young Australian of the Year Finalists