Shingler played youth rugby for Hendy RFC. He also played for Scarlets U18 from 2009 to 2011 and has represented Wales Under-20s at fly-half
Llanelli and Scarlets
Shingler made his competitive debut for Llanelli RFC in 2009 against Cross Keys. He played for the Scarlets in four games, two of which were pre-season fixtures against Gloucester and Worcester. He also played for the Scarlets in their LV=Cup games, against Leeds and London Irish, scoring 20 points against the Exiles. During this time he produced some quality displays for the Scarlets in the Anglo-Welsh Cup. Llanelli director of rugby Anthony Buchanan described Shingler as a kicker of "international standard".
London Irish
Shingler signed for London Irish on a two-year deal, starting in 2011–2012 season.
Return to the Scarlets
In January 2013 it was confirmed Steven Shingler would rejoin the Scarlets for the 2013–14 season
In March 2016 it was confirmed Shingler would head east of Llanelli to join rivals Cardiff Blues for the 2016–17 season, doing a straight swap with Rhys Patchell
International
Steven Shingler was born in Swansea, Wales and represented Wales Under-20's on fourteen occasions. On 17 November 2011 he stated his commitment to break into the Wales senior squad. On 5 January 2012, Shingler was named in the provisional Scotland squad for the 2012 Six Nations, based on the fact that his mother was born in Dumfries, Scotland. However, due to his appearances for Wales u-20, the WRU contested this call up, stating that Wales had officially declared their u-20 squad as their second XV at the time, which they understood made Shingler ineligible to represent any country other than Wales under the 'capture' rules. The Scottish Rugby Union defended their selection, saying that Shingler had refused to sign a document tying himself to Wales and believed he was eligible to play internationally for Scotland. However the WRU challenged this position, and the IRB ruled that Shingler was only eligible to play for Wales, and not Scotland. In May 2012 an IRB appeal hearing confirmed the earlier ruling that Shingler can only represent Wales. In May 2013 he was selected in the Wales national rugby union team 32-man training squad for the summer 2013 tour to Japan. He was also selected for the full national squad tour to South Africa in June 2014.