Smith signed professionally for Dundee United in July 2014. He made his first team debut against Partick Thistle in a Scottish Premiership match on 10 May 2016.[2]
Smith was given a first team chance for Dundee United in July 2017 due to injuries to other forwards. He scored his first goal for the club against Cowdenbeath in the Scottish League Cup,[5] but an injury in training ruled him out of the subsequent Dundee derby and for the next six weeks.[6] His first league goal for United came in a 2–1 defeat at Livingston in February 2018.[7] A 20-yard strike he scored in a 3-1 victory against Queen of the South was voted Dundee United's goal of the 2017-2018 season at the club's annual awards.[8] On 29 May 2018, it was announced that Smith had signed an extension to his contract at Dundee United until May 2020.[8] The club's manager Csaba László welcomed the news and commented Smith had 'shown he can be an essential player for us.[8]
On 15 August 2019, Smith joined Cove Rangers on loan until January 2020.[9] Smith left Dundee United in January 2020 and signed for Irish club Waterford.[10] In January 2021 he was transferred from Waterford to another Irish club, St Patrick's Athletic, where he would team up with former Dundee United teammate Billy King.[11] He made his debut for the club in the opening game of the season, a 1–1 draw away to Shamrock Rovers in a Dublin derby on 19 March 2021.[12] Smith scored his first goal for the Saints on 23 April 2021, heading home the second goal in a 2–0 win away to Finn Harps at Finn Park.[13] On 8 August 2021, he scored his sixth and seventh goals of the season in a 4–1 win away to Dundalk at Oriel Park.[14] Smith scored in the FAI Cup Semi-final on 22 October 2021 to give his side a 2–1 lead over Dundalk in an eventual 3–1 win to earn a place in the 2021 FAI Cup Final.[15] A week later, on 29 October 2021 he scored his first career hat-trick, scoring a perfect hat-trick in a 4–1 win away to Longford Town as well as assisting the other goal in a win that secured UEFA Europa Conference League football for his club for the following season.[16][17] On 28 November 2021 Smith was in his sides starting XI in the 2021 FAI Cup Final, as they defeated rivals Bohemians 4–3 on penalties following a 1–1 draw after extra time in front of a record FAI Cup Final crowd of 37,126 at the Aviva Stadium.[18]
On 31 January 2022, Smith signed a two-year contract with Derry City.[19] He made his career debut in European competition on 7 July 2022 against Riga FC in the UEFA Europa Conference League but was harshly sent off during a 2–0 loss for an altercation with Ngonda Muzinga.[20]
On 28 July 2022, he signed for Shelbourne on loan until the end of the season.[21] After 2 goals in 15 appearances in all competitions during his loan spell, on 2 December 2022, it was announced that Smith would be joining Shelbourne on a permanent basis for the 2023 season.[22] His first goal of the season coming on 10 April 2023 in a 2-1 win against Sligo Rovers.[23] On 6 September 2024, Smith ended a 15 month goal drought when he opened the scoring in a 1–1 draw away to Bohemians with his first goal in 33 games.[24]
On 6 December 2024, Smith returned to Waterford on a multi-year contract.[25]
^"Matty Smith Joins Cove on Loan". The Official Website of Dundee United Football Club. Dundee United Football Club. 15 August 2019. Retrieved 16 August 2019.