As nouns the difference between ultranationalism and fascism

is that ultranationalism is extreme nationalism, the belief in the superiority of one's nation and of the paramount importance of advancing it while fascism is a political regime, having totalitarian aspirations, ideologically based on a relationship between business and the centralized government, business-and-government control of the market place, repression of criticism or opposition, a leader cult and exalting the state and/or religion above individual rights. Originally only applied (usually capitalized) to Benito Mussolini's Italy.