Busan is served by Gimhae International Airport (PUS), South Korea's second-largest airport and the primary air gateway for the southern part of the country. It receives a comprehensive network of domestic arrivals, extensive connections from across East and Southeast Asia, and a growing number of direct long-haul routes. For travelers coming from within Asia, PUS can be very affordable; from outside Asia, connecting through Seoul (ICN) is often cheaper.
The busiest arrival route into Busan is the domestic shuttle from Seoul, served from both Gimpo (GMP) for domestic connections and Incheon (ICN) for international travelers connecting from long-haul flights. Key international arrival destinations include major hubs like Tokyo (NRT, HND), Osaka (KIX), Shanghai (PVG), Hong Kong (HKG), Bangkok (BKK), and Singapore (SIN). Direct long-haul arrivals operate from cities such as Los Angeles (LAX), Honolulu (HNL), Vienna (VIE), and Frankfurt (FRA), with seasonal variations — these are convenient but rarely the cheapest way to reach Busan from outside Asia.
Gimhae International Airport is a focus city for several airlines. Domestic carriers like Korean Air and Asiana Airlines operate from Seoul (GMP/ICN) to PUS, but the real action is from low-cost airlines: Air Busan, Jin Air, and Jeju Air offer frequent and affordable arrivals from Jeju Island, Seoul, and other Korean cities. International low-cost carriers such as T'way Air (from Tokyo, Osaka), Peach Aviation (from Tokyo, Osaka), and VietJet Air (from Ho Chi Minh City, Hanoi) compete aggressively on regional routes, often undercutting full-service carriers by a wide margin. Full-service international airlines including China Eastern (from Shanghai), Japan Airlines (from Tokyo), and Thai Airways (from Bangkok) also serve PUS, but they are rarely the cheapest option.
To secure cheap flights to Busan, book domestic arrivals from Seoul (GMP/ICN) a few weeks in advance — this route is so frequent (dozens of flights daily) that last-minute fares can still be reasonable. For international arrivals from within Asia (e.g., Tokyo, Osaka, Shanghai, Bangkok), aim to book 2–4 months ahead, especially on low-cost carriers. Be flexible with dates; flying into Busan on weekdays (Tuesday–Thursday) is often cheaper than weekends. Use flight comparison tools to check all airlines, especially low-cost carriers for regional Asian routes. For destinations beyond Asia (e.g., from North America, Europe, or the Middle East), compare the cost and convenience of a direct long-haul flight into PUS (e.g., from LAX or FRA) against flying into Seoul-Incheon (ICN) first. ICN offers a vastly wider range of long-haul flights and often more competitive fares, especially from the US. From ICN, a separate domestic flight or the KTX high-speed train (about 2.5 hours) to Busan may be cheaper and offer more flexibility.