Telefónica Deutschland has named Santiago Argelich Hesse as its new Chief Executive Officer, effective 1 January 2026.
He will succeed long-time CEO Markus Haas, who will leave the company at the end of December 2025 after nearly three decades with the German subsidiary of the Spanish telecoms group.
The appointment, approved by the Supervisory Board at its meeting on 7 November, marks a significant leadership change as the company positions itself for its next phase of transformation and growth. Argelich, a seasoned telecommunications executive, joins from Cellnex, where he spent the past seven years, most recently as CEO of Cellnex Poland.
“Santiago Argelich Hesse has extensive expertise in the telecommunications and digital industry as well as in leading companies through change processes,” said Peter Löscher, Chairman of Telefónica Deutschland’s Supervisory Board. “This expertise is essential for Telefónica Deutschland’s further transformation and growth strategy.”
Löscher thanked outgoing CEO Markus Haas for his “extraordinary commitment” and “significant achievements” during his nine years at the helm, crediting him with turning Telefónica Deutschland into one of the country’s leading network operators and boosting both network quality and customer satisfaction.
Haas joined Telefónica nearly 30 years ago and became CEO in 2017, steering the company through the integration of E-Plus, one of the largest mergers in the German telecoms market. Under his leadership, Telefónica Deutschland – which operates under the o2 brand – expanded its customer base, rolled out 5G and fibre networks, and cemented its position as Germany’s third-largest telecommunications provider behind Deutsche Telekom and Vodafone.
Argelich, an engineering graduate of the Polytechnic University of Catalonia in Barcelona, led Cellnex Poland through a period of rapid expansion, growing the company to hold more than 50% of the country’s telecoms infrastructure market.
“It is an honour for me to lead Telefónica Deutschland into the future,” Argelich said. “The team has achieved great things in recent years, connecting the most people in Germany with mobile communications. This is an excellent basis for taking the next steps in growth and transformation.”
