[1] Primarily active on the theatre stage for the first twenty years of his career, he is most recently and popularly known for portraying the gangster, Leonard "Lenny" Murdoch, in BBC Scotland's award winning drama River City.
Gallagher's love of history, English and modern studies didn't seem to provide the kind of knowledge that would help with finding a career, which led to his dismissal of education at the time.
Coming of age in Coatbridge in the late 1970s was difficult from a socio-economic perspective, as the town had relied heavily on steel mills, which were all closing, leaving career options and futures uncertain.
This led to involvement in youth theatre groups, which eventually developed into a career path, via a successful audition at the Royal Scottish Academy of Music and Drama.
[2] Prior to Gallagher's current television success with River City, he had recurring roles in Taggart, first as "Bruce McKenzie" (1990), then as "DI Malcolm" (1995), and later playing other characters throughout the run of the programme, lastly credited in 2010 appearing as "Charlie Muir."