Oldfield is of Tongan and European descent and attended Harbord Public School as a junior and later attended Cromer High School. For years 11 and 12, Oldfield was offered a sport scholarship to The Scots College. During his time at Scots, Oldfield predominantly played rugby union.
Oldfield played 34 games for the Manly-Warringah Sea Eagles National Youth Competition team over the 2009 and 2010 seasons, scoring 23 tries.
Oldfield made his debut for the Sea Eagles in round 23 of the 2010 NRL season against the St George Illawarra Dragons. In 2011, in each of the games he played, he scored a try. Along with fullback Brett Stewart, Oldfield was regarded as one of the fastest runners not only at Manly but in the NRL.
Oldfield traveled with the Sea Eagles to England and played in their 2012 World Club Challenge loss to the Leeds Rhinos before the start of the 2012 NRL season.
It was hoped that the flying winger would be the club's permanent replacement for long-time left winger Michael Robertson, who had left the club following the 2011 NRL Grand Final victory. Despite scoring 6 tries for the Sea Eagles in 2012, Oldfield struggled to cement his place in Manly's first grade team and was soon replaced by powerhouse rookie Jorge Taufua. This saw Oldfield only playing in 7 games for the 2012 season.
On 19 June 2012, it was announced that Oldfield had signed a two-year contract with the Sydney Roosters from 2013. Since the announcement, Oldfield was not selected in Manly's first grade team until called up due to an injury to David Williams just before the 2012 NRL Finals. Instead, finding himself in the Sea Eagles New South Wales Cup squad for most of the season.
Oldfield signed with the Sydney Roosters for 2013. After making his club debut in a 22-24 loss to the Canberra Raiders at Canberra Stadium in round 5 of the 2013 NRL season in which he scored a try, Oldfield found himself playing in the NSW Cup for the Newtown Jets.
On 20 April 2013, Oldfield, who is of Tongan heritage from his mother, made his international debut for Tonga in the Pacific Rugby League International against Samoa at Centrebet Stadium Penrith.
In December 2013, Oldfield signed a 2-year contract with the Catalans Dragons.
In the 2014 season, Oldfield scored 12 tries in just 17 games. On 14 June 2014 against St Helens R.F.C., he scored a hat trick during Catalans Dragons' 42-0 home win.
On 6 October 2015, it was announced that Oldfield had signed a 1-year contract with the South Sydney Rabbitohs.
In 2016 he made his debut for the rabbitohs from which scored only 2 tries in his last three games. Oldfield also spent time playing for Souths feeder club side The North Sydney Bears in The Intrust Super Premiership NSW making 5 appearances and scoring 5 tries. .
He then signed to the Penrith Panthers signing a 1 year deal then on the same year he granted release then on to join the Canberra Raiders on a two year deal.