The SMMWU was formed on 18 January 1959 by a group of seven industrial and clerical workers who had broken away from the pro-communist Singapore General Employees Union (SGEU). The Union was registered on 11 February 1959 with only 300 members in three branches, viz; the Singapore Glass Factory, Malayan Stevedoring and Malayan Electro Plating Company. T. Vincent Gomez became the first Secretary General of the Union.

On 21 February 1970, the SMMWU gave up 10,000 of its members in the industrial branches and a sum of $50,000, to set up an industrial Union known as the Industrial Labour Organization of Singapore. This name was changed to The Singapore Industrial Labour Organization (SILO), in December 1973. SMMWU was originally established to represent both white and blue collar workers. However, after the formation of SILO, it was decided that SILO would represent the blue collar or industrial workers while SMMWU would represent mainly white-collar workers.

Today, the SMMWU is the largest union affiliated to NTUC representing mainly commerce & service workers in the private sector.

Our Union logo:

Our logo symbolises the ideals and achievements of our Unions:

The wheel represents the turn of progress of our workers and the advancement of our Union;

The three rings represent workers' solidarity;

The yellow star symbolises bright future and a clear vision, while the red background represents equality.