Martin Compston grew up in his hometown of Greenock, in Inverclyde (a part of Renfrewshire). He spent his teen years going to see his soccer team Celtic with his brother Barry and dreamed one day he would play for them. He attended St. Columba's High School in Gourock, Inverclyde, in which he passed through his Standard Grade Exams and obtained 3 "A"s and 2 "B"s in his Higher results. He left school after his fifth year to pursue his dream as a footballer and was soon signed by Morton Football Team.

In 2000, director Ken Loach discovered him at an audition at his old high school and gave him the lead role in Sweet Sixteen (2002). The movie was filmed in Martin's home area including: Greenock, Gourock, Inverkip, Kilmalcolm and Wemyss Bay. The film was a huge success which shot Martin into full view of the public and even gave some fame to Inverclyde. However, many councillors thought that this was bad publicity as the film was to do with drugs and underage drinking. However, Ken Loach then made a statement that the movie was not based on Greenock and Inverclyde - but was only filmed there, as that was where Martin was located.