[citation needed] He was voted Scottish Football League Young Player of the Month for December 2012 after scoring three times since his first appearance.

[4][5] Together with Queen's Park teammate Andrew Robertson, Connolly signed for Scottish Premiership club Dundee United in June 2013.

[citation needed] Retaining his place in the next match against St Mirren, he contributed to all three of United's goals on his first Premiership start.

[11] On 28 June 2016, Connolly joined newly relegated National League club York City on a two-year contract, having previously played under manager Jackie McNamara at Dundee United.

[12] On 21 May 2017, he came on as a 69th-minute substitute as York beat Macclesfield Town 3–2 at Wembley Stadium in the 2017 FA Trophy Final, scoring the winning goal in the 86th minute after forcing Jon Parkin's shot over the line from centimetres out.