The official flags of El Salvador and Nicaragua are both equal blue-white-blue tricolours. Each flag has its nation's national emblem in the centre of the flag's white stripe. Along with these similarities, another Central American nation, Honduras, also has a blue-white-blue tricolour.

This is the case in the flags of Honduras, Guatemala, El Salvador, Costa Rica, and Nicaragua. These countries were once known collectively as the United Provinces of Central America. Their national flags all share the blue and white colors of the UPCA flag.

Central America was a unified nation at several points throughout its history, and while united, the country has used several national flags. The design of the Central American flag, a blue and white horizontal triband, was inspired by the flag of Argentina.