Konstantinos Thymianis was born on February 28, 2001 in Olympiada Ptolemaida and started his career in the youth setup of Iraklis Ptolemaida, then he moved to Xanthi. He has played for Greece at all age groups from Under-16 to Under-21, scoring a total of four goals.

Thymianis made his professional debut with Xanthi on 26 September 2018, in a Greek Cup match against OFI, and he has since played in 57 matches for the Thracian side, scoring two goals and providing one assist. In the 2021-22 season, he was named the top young player in the northern group of Super League 2.

On September 14, 2022, Thymianis was released and signed a two-year contract with Panserraikos. The young defender quickly became a key player for the Serres team and contributed greatly both to promotion to the top division and to Panserraikos‘ excellent run in the Stoiximan Super League last year, which saw them finish seventh. In total, Thymianis played 50 matches with the Serres club, scoring four goals and contributing one assist.