South Korea's biggest carrier in a regulatory filing said it will buy 20 Boeing 787-10s and lease 10 Boeing 787-9s.
The deal, also jointly announced at the Paris Airshow on Tuesday, gives a needed boost to the world's largest planemaker, which has suffered a sales drought following the grounding of its 737 MAX jets in March after two deadly crashes.
"The 787 Dreamliner family will become the backbone of our mid- and long-haul fleet for many years to come," Korean Air Chairman Walter Cho was quoted as saying in a statement.
The 787 planes will replace the carrier's existing aircraft such as its A330s, B777s and B747s, Korean Air said.
(Reporting by Hayoung Choi; Editing by Shri Navaratnam and Christopher Cushing)