Early career Gillespie was part of the academy setup at
Newcastle United before moving to Carlisle United in 2008, at the age of 16. He started at Carlisle as a youth team player before graduating to the reserve team.
Carlisle United On 20 February 2010, Gillespie was named as a substitute for Carlisle's
League One match against
Swindon Town due to an injury suffered by
Lenny Pidgeley. He was on the bench for a further seven games before Pidgeley returned for the 2010
Football League Trophy final on 28 March 2010. On 8 May 2010, the final day of the 2009–10 season, Gillespie made his professional debut in a win against
Norwich City at Carrow Road after coming on as a late substitute. Gillespie therefore became the youngest keeper ever to represent Carlisle, at 18 years and 42 days, beating the previous record set by
Tony Caig. In the 2010–11 season, Gillespie joined
Blyth Spartans, then in the
Conference North, on a month-long loan. He made his first start against Eastwood Town on 16 October 2010, keeping a clean sheet. His loan was extended for a further two months before he returned to Carlisle. He made no appearances for Carlisle in either of the 2010–11 or 2011–12 seasons. Gillespie made his first start for Carlisle in Carlisle's
Football League Trophy tie against
Preston North End on 4 September 2012. This ended a run of 146 consecutive starts for
Adam Collin. Gillespie retained his place in the team the following Saturday, in a league fixture against
Hartlepool United, after Carlisle manager
Greg Abbott said that Gillespie and Collin were competing against each other for the goalkeeping position. Gillespie was praised by Tottenham Hotspur boss
André Villas-Boas and veteran keeper
Carlo Cudicini after Carlisle slipped to a 3–0 defeat in a
League Cup tie on 26 September. The praise was earned after Gillespie pulled off a string of fine saves to keep United in the match early on. Gillespie lost his place in the first team at the start of November 2012, after playing 13 consecutive games in two months, during which he conceded 23 goals and kept only one clean sheet (in a game against
Crewe Alexandra on 18 September 2012). He regained his place in the team one and a half months later in a 2–1 loss at
Shrewsbury Town and retained it to make 37 appearances for the season. During the season, he extended his contract until the end of the 2014–15 season, while at the season's end, Collin departed the club for
Rotherham United. Gillespie's 2013–14 season was curtailed by a knee injury suffered in an
FA Cup tie against
Boreham Wood in November. He made no further appearances for Carlisle during the season, as the club was relegated to
League Two. Gillespie turned down a new contract from Carlisle on 7 June 2017, instead moving on to Walsall in League One.
Walsall On 23 June 2017, Gillespie joined
League One side
Walsall on a two-year contract.
Motherwell On 5 June 2018, Gillespie signed for Scottish Premiership club
Motherwell on a two-year deal. He made his debut on 17 July 2018, in a
Scottish League Cup group stage match at home to
Edinburgh City, but was backup to
Trevor Carson in league matches until November 2018 when Carson was ruled out with
deep vein thrombosis. During the season Gillespie saved a penalty on four occasions; at home against
Celtic, two in matches against
St Johnstone, and at home to
Livingston in the final game of the season. On 31 May 2020, Motherwell announced that Gillespie (who had been ever-present that season) would be leaving the club after his contract expired.
Newcastle United On 3 July 2020,
Newcastle United announced the signing of Gillespie on a three-year contract, returning to the club after twelve years. His first team action has been limited to three League Cup appearances in 2020/21 but has appeared on the bench, most notably in the League Cup Final in 2023 with Nick Pope suspended, Martin Dubravka cup-tied and Karl Darlow away on loan. On 30 May 2024, the club announced it had extended the player's contract by a year. On 6 June 2025, Gillespie signed a further one-year contract with Newcastle. ==Career statistics==