Whitehead played junior rugby league for West Bowling before being signed by his hometown professional club Bradford Bulls in 2005. Whitehead made his Super League début in June 2009 against Wakefield Trinity, and went on to make seven appearances in the final ten games of the season. He scored his first try for Bradford in July 2009 against Crusaders, and was rewarded with an improved contract with the club. against the Catalans Dragons in 2010 In the 2010 season, Whitehead featured in 26 consecutive games from Round 2 to Round 27. He also played in the Challenge Cup games against Dewsbury, Leigh and Warrington. Whitehead scored against Castleford, Hull Kingston Rovers, Leeds, Crusaders, Harlequins RL, Salford, Wakefield Trinity and Dewsbury. In the 2011 season, Whitehead featured in 24 consecutive games from Round 1 to Round 24. He has also featured in the Challenge Cup games against Halifax and Wigan. He scored tries against Leeds, Wigan, Warrington, Harlequins RL and Halifax. In August 2011, Whitehead received a five-game suspension after being charged with biting Hull Kingston Rovers forward Jordan Cox. In the 2012 season, Whitehead missed Round 1 due to suspension. Whitehead featured in 26 consecutive games from Round 2 to Round 27. He also featured in the Challenge Cup against Doncaster and Warrington. Whitehead scored tries against Wakefield Trinity, St. Helens, Salford, Doncaster, Leeds, Wigan, London Broncos, Warrington and Hull Kingston Rovers. In March 2012, Whitehead signed a new five-year contract with the club. In the 2013 season, Whitehead featured in 17 consecutive games from Round 1 to Round 17. Whitehead featured in the Challenge Cup against Rochdale Hornets and London Broncos. Elliott scored against Widnes, London Broncos and Rochdale Hornets. In June 2013, Whitehead handed in a transfer request, and was placed on indefinite leave by head coach Francis Cummins. After turning down an offer from Salford, he was signed by Catalans Dragons for an undisclosed fee.
Catalans Dragons
Whitehead signed a -year deal with Catalans, and he made his début for the club in July 2013 against London Broncos. He played eight games for the club during the season, and featured in the playoffs against Hull FC. He scored his first try for the club against Salford. in 2014 In the 2014 season, Whitehead featured in Round 1 to Round 6. Elliot featured in Round 8 to Round 10 and then in Round 13 to Round 25. Elliott next played in Round 27. He played in the Elimination Playoff. Whitehead also featured in Round 5 of the Challenge Cup. He scored against Hull F.C., Wakefield Trinity, Huddersfield, Widnes, Hull Kingston Rovers, London Broncos, Bradford Bulls, Wigan and Castleford. In the 2015 season, Whitehead featured in Round 1 to Super Eight 7. Elliott played in the Challenge Cup in Round 6 and the Quarter Final. He scored against Castleford, Salford, Leeds, Wakefield Trinity, Hull Kingston Rovers, Warrington, Widnes and Hull F.C..
Canberra Raiders
On 8 April 2015, Whitehead signed a two-year contract with National Rugby League side Canberra Raiders starting in 2016. He made his début against Penrith Panthers, and went on to play 27 games and score 6 tries in his first season in the NRL. In August 2016, he was given a contract extension until the end of 2018. Whitehead credits his ability to adapt to the Australian style of play on personal fitness guru Chris Anderson. At the end of the 2017 season, Whitehead extended his contract with Canberra until the end of the 2020 season. Whitehead made 27 appearances for Canberra in the 2019 NRL season as the club qualified for their first grand final in 25 years. Whitehead played in the 2019 NRL Grand Final at second-row as they were defeated 14-8 by the Sydney Roosters at ANZ Stadium.