Miller Thomson joined the Dundee United Academy at the age of 11 from local club East Fife and graduated through the Scottish Football Association Performance School at St John's Roman Catholic High School in Dundee.
[2] He made his first team debut aged 17, as a substitute in a 3–0 Scottish Cup defeat against Celtic on 14 March 2022.
[3] In United's next match, away to St Mirren in the Scottish Premiership, Thomson made his first starting appearance, but was substituted at half time.
[5] In August 2024 Thomson scored his first goal for United in a 2-2 draw with city rivals Dundee at Tannadice.
[6] On 3 February 2025, Thomson joined Scottish Championship club Falkirk on loan until the end of the season.