Scottish Omnibuses was set up in 1949 by the British Transport Commission (which had been established by the Transport Act, 1947, as part of the nationalisation of transport).

Scottish Omnibuses became the parent company for all nationalised bus companies in Scotland, including SMT and its subsidiaries, such as W Alexander & Sons Ltd and David Lawson Ltd.

In 1961 the British Transport Commission created a new holding company, Scottish Omnibuses Group (Holdings), to take control of the British Transport Commission's bus operating subsidiaries in Scotland.

In 1962 the group became part of the Transport Holding Company when the British Transport Commission was wound up.
The group was renamed Scottish Bus Group in 1963 and became part of the Scottish Transport Group on 1st January 1969, together with David MacBrayne Ltd