Kostiantin
Fewer than a hundred men in Poland carry it, all of them male, and most Poles have never met one. Ukrainian in use, Greek at root, from a name meaning "constant, steadfast".
Kostiantin Pronunciation
Kostiantin is pronounced kost-YAHN-teen (/kɔstˈjantin/).
What Kostiantin means
Where Kostiantin comes from and what it has meant to the people who carry it.
Kostiantyn came to Ukraine in Greek dress, as Konstantinos, a name worn by Byzantine emperors whose faith moved north along the Dnipro. The form carried an old sense of steadfast. Constantine the Great, who gave his name to a whole city, fixed that meaning in imperial gold. From the Greek Konstantinos the name passed into Church Slavonic, and Ukrainian settled on Kostiantyn.
Polish keeps the name in two variants, Konstanty and Konstantyn, and shortens it to Kostek in a school register. The cross-gender partner is Konstancja. In Ukrainian history the name belongs to Kostiantyn Ostrozky, the prince who founded the Ostroh Academy in 1576 and defended Orthodox learning against every pressure to convert.
The meaning stays plain. Constant, steadfast, and slow to move.
How many people are named Kostiantin
1 in 284616 men in Poland is named Kostiantin. 75 people carry it in the 2025 register: rank #4130 among male names.