Jason turned Professional in 2006 after an outstanding amateur career. He immediately started playing on the PGA TOUR.
In 2007 Jason earned status on the Web.com Tour where he won his first Pro tournament in his first start on the secondary tour.
Earning a PGA TOUR card for 2008 he had his break through victory in 2010 when he became the youngest Australian to win on the PGA TOUR. Day made his Presidents Cup debut in 2011 and despite not winning a tournament that year had an outstanding season with two runner-up finishes in the Majors. Day has become a consistent performer at the Majors and is regularly in contention. However his third Professional victory eluded him until he teamed up with compatriot Adam Scott at the World Cup of Golf in 2013.
Back in Australia in the World Cup of Golf held at Royal Melbourne in 2013 Jason went on to win both the individual and teams title with Adam Scott. He quickly followed this with a win at the WGC - Accenture Match Play in February 2014. Soon after his victory Day was plagued by a wrist injury which has limited his play in 2014.
In 2015 Claimed his third PGA TOUR title and second stroke-play title at the Farmer Insurance Open after a four man play-off with Harris English, Scott Stallings and J.B Holmes.
- Recorded two top-5 finishes at The Masters
- Has three top-5 finishes at the US Open
- Has two top-10 finishes at the US PGA Championship since he made his Major debut in 2010.