Quinn was called up by the Republic of Ireland for the first time as part of the senior squad to face San Marino in the UEFA Euro 2008 qualifier at the Serravalle Stadium on 4 February 2007.

He made his U21 international debut in the 1–0 loss against the Netherlands in Venlo on 27 March.
Quinn scored his first international goal in a 3–2 victory against Sweden U-21 in October 2007.

Quinn won his first senior cap on 2 June 2013 when the Republic of Ireland beat Georgia 4–0.
He would also go on to win a second cap against World Cup and European Champions Spain.

On 7 September 2014 in Martin O'Neill's first competitive game in charge of Ireland, Quinn started his first competitive game against Georgia alongside Glenn Whelan and James McCarthy in midfield.
Ireland won the game 2–1 thanks to a superb last minute winner by Aiden McGeady.
Quinn admitted after the game that there was a "weight lifted off his shoulders" after making his competitive debut.
Quinn started in the memorable 1–1 draw against Germany, Quinn was criticised in the media for the German goal for standing off and allowing Toni Kroos the time to shoot and score.
Quinn was called up by the Republic of Ireland for the first time as part of the senior squad to face San Marino in the UEFA Euro 2008 qualifier at the Serravalle Stadium on 4 February 2007.
He made his U21 international debut in the 1–0 loss against the Netherlands in Venlo on 27 March. Quinn scored his first international goal in a 3–2 victory against Sweden U-21 in October 2007.
Quinn won his first senior cap on 2 June 2013 when the Republic of Ireland beat Georgia 4–0. He would also go on to win a second cap against World Cup and European Champions Spain.
On 7 September 2014 in Martin O'Neill's first competitive game in charge of Ireland, Quinn started his first competitive game against Georgia alongside Glenn Whelan and James McCarthy in midfield. Ireland won the game 2–1 thanks to a superb last minute winner by Aiden McGeady. Quinn admitted after the game that there was a "weight lifted off his shoulders" after making his competitive debut. Quinn started in the memorable 1–1 draw against Germany, Quinn was criticised in the media for the German goal for standing off and allowing Toni Kroos the time to shoot and score.
Stephen Quinn