Rosario Marchese is a former Canadian politician in Ontario, Canada. He was a New Democratic member of the Legislative Assembly of Ontario from 1990 to 2014, representing the downtown Toronto riding of Trinity-Spadina and before that the old riding of Fort York.

The 1990 Ontario general election was held on September 6, 1990, to elect members of the 35th Legislative Assembly of the province of Ontario, Canada. The governing Ontario Liberal Party led by Premier David Peterson was unexpectedly defeated. Although the Peterson government, and Peterson himself, were very popular, he was accused of opportunism in calling an election just three years into his mandate. In a shocking upset, the New Democratic Party (NDP), led by Bob Rae, won a majority government. This marked the first time the NDP had won government east of Manitoba, and to date the only time the NDP formed the government in Ontario.