Mo is a former municipality in Telemark county, Norway.
The parish of Mo was established as a municipality January 1, 1838 (see formannskapsdistrikt).
On 1 January 1964 a merger took place between Mo and Lårdal, creating the new municipality Tokke. Before the merger Mo had a population of 1,658.
The municipality (originally the parish) was named after the farm Mo (Old Norse Mór), since the first church was built there. The name is identical with the word mór m 'heath, moor'.