Walsh is from Troon, Ayrshire and joined Rangers' Academy in 2007. He made his first-team debut for Rangers on 8 December 2012, aged only 16 years and 150 days, in a Scottish Third Division match against Stirling Albion. Walsh became the youngest post-war Scottish football league debutant for Rangers and second youngest competitive debutant ever for the club, behind Derek Ferguson who made his debut in a League Cup match against Queen of the South in 1983, aged 16 years and 24 days. The following season saw Walsh suffer with injury, initially sustaining an ankle injury and then a recurring hamstring problem kept him out for the whole of the 2013–14 season After finding opportunities in the first team difficult to come by and in a bid to improve his fitness levels after a long injury, Walsh joined the then Scottish League One side Stenhousemuir on loan for the first half of the 2014–15 season. Prior to going on loan Walsh had signed a new contract extension with Rangers until 2017. He made his debut for Stenhousemuir nearly three weeks later, on 20 September, against Peterhead, after recovering from a further hamstring injury. He scored his first professional goal in his second appearance for Stenhousemuir on 18 October, against Stirling Albion, adding the fourth in a 4–0 win. After returning from his loan spell, Walsh featured once during Kenny McDowall's three months in charge of the first-team. However, upon the appointment of Stuart McCall as interim first-team manager, Walsh then began to play a more prominent role in the first-team squad. He joined fellow Scottish Championship club Dumbarton on loan in January 2016. He scored his first goal for the Sons in a 4–2 win over Queen of the South. On 17 July 2016, Walsh joined Scottish Championship club St Mirren on loan until January 2017. Walsh was released by Rangers on 18 January 2017. After leaving Rangers he played two games as a substitute for Limerick in the League of Ireland against Shamrock Rovers and Derry City. He returned to Dumbarton on a one-year deal in June 2017. After a year with Dumbarton, Walsh moved North, signing for Inverness Caledonian Thistle. Walsh rejected a new contract offer in 2020, choosing to leave the club as a free agent.
International career
Walsh has represented Scotland at various age levels.
