Konstantinos Kefalogiannis was born in Heraklion, Crete. He is a graduate of the Faculty of Law and the School of Political Sciences of the Aristotle University of Thessaloniki. He has completed his military service, serving in the Special Forces, specifically in the 1st Amphibious Raider Squadron in Rhodes and Kastellorizo, and in the 2nd Paratrooper Squadron in Aspropyrgos. He was an active member of DAP-NDFK and served as Head of International Relations of ONNED Thessaloniki, representing the youth organization of New Democracy at numerous conferences in Greece and abroad. He was later appointed Coordinator of Productive Sectors of New Democracy. He has worked at the European Parliament and in law firms in Thessaloniki and Athens. In 2023, he was elected Member of Parliament for Heraklion. Shortly thereafter, he was elected Secretary of the Hellenic Parliament. He serves on the Committee on European Affairs, the Committee on Cultural and Educational Affairs, and the Special Committee on Youth, Equality and Human Rights. He is also Vice-Chair of the Greece–Iraq Friendship Group.