The Institute of Materials, Minerals and Mining (IOM3) is a major UK engineering institution whose activities encompass the whole materials cycle, from exploration and extraction, through characterisation, processing, forming, finishing and application, to product recycling and land reuse. It exists to promote and develop all aspects of materials science and engineering, geology, mining and associated technologies, mineral and petroleum engineering and extraction metallurgy, as a leading authority in the worldwide materials and mining community.

IOM3 was formed from the merger of the Institute of Materials and the Institution of Mining and Metallurgy in June 2002. Its roots go back to the Iron and Steel Institute which was established in 1869. It received Royal Charters in 1899 and 1975. It merged with the Institute of Packaging (2006) and the Institute of Clay Technology (2006). In the Summer of 2009 the Institute reached an agreement with the Institute of Wood Science to transfer all its members and activities to IOM3. In November 2010, IOM3 also embraced the activities and membership of the Institute of Vitreous Enamellers.