Rosario Kennedy was born in 1945 in Cuba. She came to exile with her family in 1960. She graduated with a scholarship from the Convent of the Sacred Heart in Greenwich, Connecticut. Her father Elicio Arguelles Menocal was a former senator of Cuba as well as her grandfather. Her great uncle Mario García Menocal was President of Cuba.

She was the first Cuban American woman on the City of Miami Commission, former Vice Mayor of the City of Miami and candidate for Florida’s 18th congressional district in 1989. In 1985, she ran for the City of Miami Commission against the incumbent, Demetrio Perez. She won that election and was later elected by her peers on the commission as Vice Mayor.