Marco Appel studied journalism in Mexico and has a specialization in European integration from the Université Catholique de Louvain-Université Saint-Louis.
Since 2001 he has been the Brussels correspondent for several Mexican national media outlets. Between 2005 and 2020, he was a correspondent for Proceso magazine. In 2000 he was a grantee in Brussels for the European Commission's Visitors Programme, and in 2006 in Berlin for the International Journalists' Programmes.
He is a co-author of the books Drogas Libres, Libres de Drogas (Mexico-Spain, 2012) and Epidemia Ultra (Germany, 2019).
Appel is also the co-founder of Underground Periodismo Internacional, a Spanish-language platform that provides international reports, interviews, and stories.