There are quite a lot of smoking areas at Incheon Airport. As normal there is no smoking in the general terminal, only in dedicated smoking areas.
Adjacent entrance 8 in the Passenger Terminal
There are no locations shown on the Airport Map for 2F. If you find an area please leave it’s location in the comments below.
Near Gates: 10, 12, 23/15, 30, 32/40, 45, 127/128