Scragh Bog is a national nature reserve of approximately 56 acres (0.23 km2) in County Westmeath.

It is considered Ireland's best example of a habitat transitioning from an alkaline fen to an acidic raised bog, and is deemed to be of international importance.

Scragh Bog was legally protected as a national nature reserve by the Irish government in 1992.

A large number of rare flora and insects in Europe have been recorded in the reserve.

[3] The creation of the nature reserve was cited as the reason that a number of rare insects have been conserved in Ireland.