In 1911, he was appointed Lecturer in Applied Electricity at Hamilton Technical School, located at Hamilton Academy, and taught in the Academy's senior school, one of his pupils being Thomas Cassells, who was also to serve as a Labour MP (for Dunbartonshire, and for the same period, 1936–41).

In 1915, shortly after the outbreak of the First World War, Gibson joined the Royal Garrison Artillery as a lieutenant.

[1] He rose to the rank of Captain but did not see active service, being returned to the Technical Training Staff of Scottish Command.

Gibson was an unsuccessful candidate in Roxburgh and Selkirk in 1929,[5] Edinburgh North in 1931,[6] at the Combined Scottish Universities in a 1934 by-election,[7] and Dundee in the 1935 general election.

[8] He was elected as Member of Parliament (MP) for Greenock at a by-election in 1936,[9] and held his seat until he resigned from the House of Commons in 1941 on his appointment as Chairman of the Scottish Land Court.