In all the world, Koláček (Koláček 
) is an extremely rare unknown gender first name. Much more frequently, Koláček is the last name as well as the forename.
Jan, Martin, Marcel, Michal, Patrik, Daniel, Dušan, Luděk, Luboš, Jiří, Michael, Břetislav, Dalibor, Gabriel, Lukáš, Tomáš, Václav, Ondřej, Zdeněk, Miroslav, Antonín, Kryštof, Yosef, Ondra, Filip, Honza, Ing, Ivo, Adam, Kuba, Petr, Marek, Milan, Mirek, Aleš, Karel, Ladislav, Kamil, Peter, Radim, Radek, Roman, David, Leoš, Libor, Jakub, Josef, Jenda, Pavel, and Jaroslav