The seats will be available on services from Poland, Slovakia, Hungary and Romania throughout March.
In a statement issued on Tuesday (1 March), the airline said it was "committed" to helping Ukrainian refugees reach their destination, "wherever that may be".
The carrier will also offer a €29.99 rescue fare on all other flights (excluding the UAE, Iceland and the Canaries), as well as a €69.99 rescue fare on all flights to the UAE, Iceland and the Canaries, to support refugees who may be stranded in other locations.