Athanasios K. Tsakalidis (Greek: Αθανάσιος Κ. Τσακαλίδης; born 1950) is a Greek computer scientist, from Katerini in northern Greece.
Although his first studies were in mathematics at the Aristotelian University of Thessaloniki, he earned a second degree in Informatics at the University of Saarland, Germany. He earned his Master's (thesis: "Sorting Presorted Files") from this University, along with a PhD in Computer science, with a thesis entitled "Some Results for the Dictionary Problem", which he completed under Professor Kurt Mehlhorn, director of the Max Planck Institute for Informatics.
He returned to Greece after participating in research work for the DFG (Deutsche Forschungsgemeinschaft, the German community of research) and professional teaching at the University of Saarland related to Data Structures, Graph Algorithms, Computational Geometry and programming. In Greece, he was given the chance to successfully back-up his work by becoming a professor at the University of Patras, where he is currently living and teaching. Since then, he has helped the general introduction of informatics to Greece, and is head of the faculty.
His research interests include: Data Structures, Graph Algorithms, Computational Geometry, GIS, Medical Informatics, Expert Systems, Databases, Multimedia, Information Retrieval, and Bioinformatics.
He has also participated in many EU research programs: ESPRIT, RACE, AIM, STRIDE, Basic Research Actions in ESPRIT, ESPRIT Special Actions, TELEMATICS Applications, ADAPT, HORIZON, ΕΠΕΤ ΙΙ, ΥΠΕΡ, ΤΕΝ – TELECOM, IST, LEONARDO DA VINCI, MARIE CURIE, SOCRATES.
He was also a visiting professor at King's College London (2003–2006).
He is one of the 48 writers of a computer science book, Handbook of Theoretical Computer Science, Vol 1 Elsevier Science publishers, co-published by MIT Press, his work being, along with professor Kurt Mehlhorn, in Chapter 6: Data Structures (his favourite field).