Career
Shaughnessy has also previously played for Aberdeen and on loan for Forfar Athletic and Falkirk. He has represented the Republic of Ireland national under-21 football team at international level Aberdeen
Shaughnessy signed for Aberdeen in June 2009, having previously played for Irish club Salthill Devon as a youngster.
Shaughnessy made his debut on 14 May 2011 against Hibernian.
A few days before making his debut, he signed a contract extension on a two-year deal. On 30 August 2011, Shaughnessy went on loan to Forfar Athletic until January, along with Nicky Low.
Shaughnessy would score twice in two games. In a 4–3 loss against East Fife on 1 October 2011 and another in a 1–1 draw against Arbroath on 15 October 2011.
After impressing on loan, he went back to Forfar until the end of the 2011-2012 season.
He went on to make 26 appearance and scored three times. Ahead of the 2012-2013 season, manager Craig Brown believed Shaughnessy and Low had performed well at Forfar Athletic and considered him using them in the first team in the near future. On 7 December 2012, Shaughnessy signed a contract extension with Aberdeen until 2015.
In the 2013-2014 season, Shaughnessy played in the right-back position at the start of the season.
Shaughnessy was even compared to Richard Gough, due to his playing style. lieutenant was his first red card of his professional career and this resulted in him missing some matches.
Shaughnessy subsequently had his first team opportunities limited, as Shaleum Logan or Ryan Jack were preferred in the right-back position. Shaughnessy did not start a game for Aberdeen in the early part of the 2014-2015 season and was loaned to Falkirk.
He made his debut on 6 September 2014, as Falkirk lost 1–0 against Stranraer in the Scottish Challenge Cup.
Following his return, Shaughnessy made two more appearance, including making his first start, in a 1-0 loss against Street Johnstone in the last game of the season. On 14 May 2015, Shaughnessy was named as one of seven players who would be leaving Aberdeen at the end of the season, having not been offered a new contract. Street Johnstone
Shaughnessy signed a pre-contract agreement with Street Johnstone on 20 May 2015, agreeing a two-year deal.