Sergio Díez- Cornell is a Spanish particle physicist and staff scientist at the Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany.

He was a physics undergraduate student at Universidad de Zaragoza in Spain. He completed his Ph.D. in Physics at the Centro Nacional de Microelectrónica (IMB-CNM, CSIC) and the Universidad Autónoma de Barcelona (UAB), in Barcelona, Spain, in 2010. He was a post-doctoral researcher at the Lawrence Berkeley National Laboratory (LBNL), in Berkeley (CA), USA from 2010 to 2014. Since 2014, he is a staff Scientist in the ATLAS group of the Particle Physics division at DESY.

He is an instrumentation particle physicist and a member of the ATLAS Collaboration since 2010. His work includes the study of radiation effects on modern microelectronics technologies, microchannel cooling for particle detectors, the study of novel composite materials for large scale silicon detectors, and more recently the design and construction of the new ATLAS microstrips inner tracker for the High- Luminosity LHC.

He is also passionate about sport, reading sci-fi novels, board games, and listening to live music of all kinds.