Aged 16 MacKenzie graduated from the Thistle Weir youth academy and joined the club's first team on a two-year contract, as a modern apprentice.
[1] MacKenzie made his first team debut for Thistle in September 2022, in the Scottish Challenge Cup, coming off the bench away to Falkirk.
[2] MacKenzie made his first league appearance for Thistle as a substitute in a 3-2 home defeat to Dundee, in November 2022.
[4][5] Following a breakthrough into the first team, MacKenzie signed a three-year contract extension with Partick Thistle in July 2023.
[6][7] MacKenzie scored his first goal for Partick Thistle adding the third in a 3–0 home win over Queen’s Park in the Scottish Championship in August 2024.