The Humanist Party (PH - Partido Humanista) is a progressive, left-wing political party in Chile, founded in March 1984. They have several flags.
Esteban Rivera, 9 March 2016
Branches of the Humanist Party in other countries use very similar flags; one should be aware of the problem differentiating between the different national versions, especially in the case of Spanish-speaking countries. M. Schmöger, 23 March 2014
In response to Mr. Schmöger's comment, I skimmed the internet and found that the Partidos Humanistas of Argentina, Bolivia, Brazil, Colombia, Paraguay, Spain and Uruguay use the same logo and colour scheme as their Chilean counterpart. Those of Mexico and Peru use different logos. I wasn't able to find readily available information on other Latin American branches of the party.
Alex Garofolo, 2 February 2016