Guillermo Arias is a Mexican photojournalist based in Tijuana, Mexico, with over three decades of experience covering news, social issues, and border affairs for leading international media organizations.

He began his career as a freelance photojournalist in 1993 in Tepic, Mexico, working for local newspapers in Tepic and Guadalajara before joining the Associated Press as a contract photographer from 2001 to 2011. During that decade he covered major international assignments including Mexico's drug war (2007–2011), the FIFA World Cup South Africa 2010, presidential elections and the cholera epidemic in Haiti (2010), and the III Latin America–European Union Summit in Guadalajara (2004), among others. From 2011 to 2016 he served as Graphic Correspondent for Latin America at Xinhua News Agency, covering events of global significance: the Pan American Games Guadalajara 2011, Copa América Argentina 2011, Pope Benedict XVI's visit to Cuba (2012), the G20 Summit in Los Cabos (2012), the funerals of Hugo Chávez in Venezuela (2013), the FIFA Confederations Cup Brazil 2013, the FIFA World Cup Brazil 2014, and Copa América Chile 2015, among others. Since 2016 he has worked as an independent photojournalist and regular contributor to Agence France-Presse (AFP), and has collaborated with The New York Times, the ACLU, and other major outlets. Notable recent assignments include the official coverage of the Copa Oro 2017 in the United States, the Central American migrant caravans (2018–2019), and the Pan American Games Lima 2019.

His work has earned sustained international recognition. In 2019 he received the Prix Visa d'Or News at Visa pour l'Image — the world's most prestigious photojournalism festival — for his coverage of the Central American migrant caravans. That same year he was awarded the Istanbul Photo Awards First Place in Story News, the POY Latam First Place in Spot News Singles, and the Prix Fondation Varenne Catégorie Internationale; he also received First Place at the Premio Alemán de Periodismo Walter Reuter (Goethe Institut). Earlier distinctions include an Honorable Mention at the World Press Photo 2010 in Contemporary Issues; Honorable Mention in both Domestic News Picture Story and Domestic News Singles at the Best of Photojournalism (NPPA) 2010; an Award of Excellence in Spot News at the 67th Pictures of the Year International; the Premio Nacional de Periodismo Cultural Fernando Benítez 2009; an Honorable Mention at the Atlanta Photojournalism Seminar 2009; The Deadline Club New York City Chapter Spot News Photo 2009; Third Place at the 17th Bayeux-Calvados Award for War Correspondents; and First and Third Place distinctions at POY Latin America in the Spot News Single category (2013 and 2011). In 2021 he received First Place in Sports at POY Latam, and in 2022 an Honorable Mention at the Baja Journalism Contest (San Diego Union Tribune / UC San Diego). In 2025 his project The Border Wall and the Destroyed Landscape was selected for projection at the 37th edition of Visa pour l'Image in Perpignan, and for the temporary exhibition "Mirror, Mirror" at the San Diego International Airport Art Program.

In addition to his editorial work, Arias has a sustained commitment to journalist safety and training. Between 2012 and 2015 he participated as a trainer in the "Trainer of Trainers" program, a joint initiative between Article XIX México and World Press Photo. He completed Hostile Environment and Emergency First Aid Training (HEFAT®) in 2009, participated twice in the Taller para Periodistas en Zona de Riesgo organized by Article XIX México and the Red Cross (2008 and 2011), and in December 2025 completed a five-day HEAT training by Other Solutions Consulting in Bogotá, Colombia. He has also participated as panelist at the 15th DW Global Media Forum (Bonn, 2022), the Committee to Protect Journalists' Photoville LA panel "Safety in Focus: The US/Mexico Border" (2019), and the Centro Cultural Tijuana (2025).

His personal documentary work has been supported twice by Mexico's Sistema Nacional de Creadores de Arte (SNCA). His most recent project, The Border Wall and the Destroyed Landscape (2021–2024), examines the environmental and territorial impact of the U.S.-Mexico border wall.