[citation needed] He studied at the Colegio Yugoslavo, San José de Antofagasta English School and at Saint George's College, in Vitacura, Santiago.

[citation needed] During his studies he was nominated for the student center of his career, presiding over the independent list, which he lost against Esteban Valenzuela.

From August to December 2011, he completed an internship in the Sports Department of the University of Notre Dame, South Bend, Indiana, United States.

He is a professor at the Faculty of Engineering of the Catholic University of Chile, where he has taught courses "History of the World Cup" and "Management in Sports".

In 1993, he joined FIFA as press officer of the World Cup held the following year in the United States, specifically in the Boston headquarters.

In May 2012, he resigned from FIFA, being his last function in the latter, inspecting the nominations for the 2018 and 2022 World Cups and had been designated by the Federation as football commissioner at the London Olympics 2012 for the Cardiff headquarters, Wales.

In his period the senior team qualified for the 2010 Football World Cup held in South Africa, by the hand of Argentine coach Marcelo Bielsa, hired by Mayne-Nicholls.

[7] After his departure from the ANFP, the year 2011, Harold Mayne-Nicholls founded Fundación Ganamos Todos in order to bring sports and physical activity to all corners of Chile.