Nicolás Dionisio Castellanos Rivero (December 6, 1911 in Limonar, Cuba – February 10, 1985) was a Cuban politician and mayor of Havana from 1947 to 1952.

[1] Castellanos was the president of the Havana City Council until succeeding Manuel Fernández Supervielle as mayor.

Castellanos took office in 1947 after the mayor, Manuel Fernández Supervielle, committed suicide.

Castellanos allocated 26 million pesos to complete the third expansion of Acueducto de Albear.

[5] This visit was important as Cuba and The United States faced political troubles, with Havana and Key West having only 93 miles of separation.