The Michigan-Ontario Hockey League was a senior amateur league based in the Michigan/Ontario region of North America. The league operated from 1932 until 1942, when it was disbanded because of a lack of players due to World War 2.
The Michigan-Ontario Hockey League can be seen as the ancestor of the International Hockey League; in fact, the IHL was originally going to be called the Michigan-Ontario League, but instead went with IHL because they expected to eventually expand beyond Michigan and Ontario.