Alcalde-presidente

An alcalde-presidente is an alcalde (Spanish for municipal mayor) who also functions as president(e) of a higher administrative level.

Cases include:

As Singapore is a city-state, its president can be thought of a mayor who also functions as a president of a higher (in this case, the highest) administrative level; however, the President of Singapore, though not entirely ceremonial, is not the city-state's chief executive. The prime minister is.

Sources