Model Engineering is the hobby of constructing machines in miniature. There is some debate about the appropriateness of the term. Some say that all 'engineers' should be professionally qualified as such; however, the historic meaning of 'engineer' is one who constructs or tends engines, and as such is a fitting epithet for those who make working models as a hobby. In the United States, the term home shop machinist is often used.

The 'classic' areas of interest are live steam models (typically steam locomotives, stationary engines and traction engines, internal combustion engines, and clock making. Other popular subjects are stirling engines, miniature machine tools and ornamental turning. There have always been a significant number of model engineers whose hobby is dominated by making the tools and equipment they need for the models that they never quite finish...