Model engineering is the pursuit of constructing proportionally-scaled miniature working representations of full-sized machines. It is a branch of metalworking with a strong emphasis on artisanry, as opposed to mass production. While now mainly a hobby, in the past it also had commercial and industrial purpose. The term 'model engineering' was in use by 1888. In the United States, the term 'home shop machinist' is often used instead, although arguably the scope of this term is broader.
Model engineering is most popular in the industrialised countries that have an engineering heritage extending back to the days of steam power. That is, it is a pursuit principally found in the UK, USA, northwestern European countries and the industrialised British Commonwealth countries.