Donnelly graduated through the Port Vale youth team, and turned professional under Brian Horton. He made four First Division appearances in the 1999–2000 relegation season, and featured once in the Second Division in 2000–01, before he was released from Vale Park after playing eight league and cup games in 2001–02. He dropped out of the Football League in July 2002 to sign for Stone Dominoes of the North West Counties Football League. In his first season with the club they won promotion to the First Division as runners-up of the Second Division. He stayed for three years before joining Nantwich Town in 2005. With Nantwich he lifted the FA Vase in 2006 following a 3–1 win over Hillingdon Borough at St Andrew's. He also helped the club win promotion out of the Northern Premier League Division One South, following a penalty shoot-out win over Sheffield in the 2008 play-off final. They also won the Cheshire Senior Cup that same year after a penalty shoot-out victory over Altrincham. In all he played 95 games before joining Witton Albion three years later. In December 2008 he signed with Newcastle Town. He impressed at Town, winning the attention of Kidsgrove Athletic, however the Newcastle captain turned down the chance to play at a higher level, instead choosing to stay with Town. In 2009–10 his side won promotion to the Northern Premier League Division One South, after finishing top of the North West Counties Football League Premier Division. Town finished 24 points clear of second place New Mills. In 2010–11 he led Town to a second-place finish, though they lost 3–0 to Grantham Town in the play-off semi-finals. In 2011, he joined Northern Premier League Premier Division side Stafford Rangers, whilst also working as an administrator at Staffordshire University. He captained Rangers to a 16th-place finish in 2011–12. He left the club in May 2012. Two months later, he signed with Kidsgrove Athletic. He helped "Kiddy" to an 18th-place finish in the Northern Premier LeagueDivision One South in 2012–13. He signed with league rivals Leek Town in July 2013. He helped the "Blues" to secure a play-off spot with a third-place finish in 2013–14, where they were knocked out by Belper Town at Harrison Park. They again reached the play-offs in 2014–15, losing to Sutton Coldfield Town in the final. Donnelley re-joined Kidsgrove Athletic in May 2015 after being signed by manager Peter Ward. Kidsgrove finished in 15th place in 2015–16.
Coaching career
Donnelley joined Leek Town as manager Anthony Danylyk's assistant in May 2016. In June 2017, he followed Danylyk to Leek's Northern Premier League Division One South rivals Belper Town. The pair left the club five months later, citing a change in personal circumstances.
