H.M. Factory Inspectorate, which became part of the Ministry of Labour, was established in 1833 as part of the Home Office. The first factory inspectors were appointed by King William IV. The Inspectorate increased in size and scope throughout the 19th century, particularly as Parliament passed various Factory Acts in 1844, 1861, 1864, 1867 and 1871.

The Factory and Workshop Act of 1878 was significant, as it brought almost all of manufacturing industry within the scope of the law, defining three official categories of Textile Factories,Non-Textile Factories and Workshops. The Factory Inspectors were now responsible for ensuring a much greater degree of health, safety and welfare for workers across Britain. Inspectors took on an advisory role, and educating employers about improved fencing of machinery and methods of accident prevention became a defacto part of an inspector's remit.

As factory technology evolved and became more specialised, the Inspectorate created roles for specialists in particular types of machinery in the late 19th century. The first female factory inspectors, known initially as ‘Lady Inspectors’ were appointed at this time, taking office in 1893.

The Inspectorate was transferred temporarily from the Home Office to the Ministry of Labour in 1940, as part of wartime reorganisation. The government made the move permanent in 1946, as it made sense to unite responsibility for health and safety law with responsibility for employment law under one Ministry. The Inspectorate would remain part of Labour or Employment ministries, with the exception of a brief spell in the 1990s when it came under the Department for Environment, Transport and the Regions.

The influential Health and Safety at Work Act of 1974 led to the creation of the Health and Safety Executive (HSE) on 1 January 1975. The Factory Inspectorate transferred to HSE at this time, along with other bodies including Explosives Inspectorate, Employment Medical Advisory Service and Mines Inspectorate, amongst others.