The flight service will be available three times a week - on Tuesday, Thursday and Saturday, starting from 16 May to 26 October.
The airline's 347-seat Airbus A330-300 planes will be landing in Zagreb at 7.55 pm and leaving for Seoul at 9.25 pm.
Tickets can be booked at www.twayair.com.
The last regular flight between Zagreb and Seoul was in late November 2019.
After Zagreb, T'way Air will also introduce flights to Paris, Rome, Barcelona and Frankfurt.