Konstantinos Gelaouzos is a Greek long-distance runner. He was born on 21 November 1990 in Amfissa and resides in Athens. His personal best in the Marathon run (2:14:15) places him in the fifth place among all time Greek Marathon runners.
On 14 November 2021, with a time of 2:16:49 during the 2021 Athens Classic Marathon, he set the record for the fastest Greek runner of all time that has run the classic route.
Gelaouzos was punished by the National Anti-Doping Organization (EOCAN) with a four-year ban, effective from December 1, 2022 to November 30, 2026, for using the banned substance erythropoietin 4 years ineligibility.