Top 10 Best Media Buying Agencies in Korea 2026

Korea's advertising market is one of the most concentrated in Asia, and the top media buying agencies in Korea reflect that structure. Chaebol-affiliated in-house media arms dominate the upper tier, independent digital specialists control the performance-marketing middle, and global network agencies handle multinational brands entering the market. To build this ranking, we weighed several factors: gross billings and revenue where public financials exist (2023-2024 filings), digital and programmatic infrastructure, client roster depth, and placement in 2026 agency directories including Clutch.co, DesignRush, GoodFirms, and Manifest. We also factored in market position, since a captive Samsung or LG account provides scale that independent shops cannot match. Where 2026 Korea-specific media buying figures are not uniformly published, we relied on the most recent verifiable data and noted the date. The result is a list that separates the conglomerate giants from the specialist buyers, with each entry judged on what it actually does best.

The Top 10 Best Media Buying Agencies in Korea 2026:

1. Cheil Worldwide (제일기획)

Cheil Worldwide is the flagship agency of Samsung Group and the largest advertising company in Korea by revenue, with approximately ₩4.3 trillion (about $3.2 billion) in 2023 gross billings. Media planning and buying is a core business line, spanning TV, digital, out-of-home, and programmatic. The agency consistently ranks among the world's top-20 agency groups.

What separates Cheil from every other buyer in the market is its in-house media representative Penguin, which gives the agency direct inventory access that outside buyers have to negotiate for. That structural advantage, combined with the Samsung account, makes Cheil the default benchmark for scale and cross-platform reach in Korea. No other agency approaches its billings or its client base.

2. HS Ad (HS애드)

HS Ad is the in-house advertising and media arm of LG Group, formed from the former LG Ad, and it ranks as Korea's second-largest agency group by revenue with more than ₩1.5 trillion in annual billings as of 2023. The agency handles integrated media planning and buying across broadcast, digital, and retail media.

Its product-launch capabilities are a particular strength, built around LG's steady cycle of consumer electronics and appliance releases, and it coordinates media for LG brands across global markets. The captive LG business provides stable scale, but HS Ad also serves non-LG clients, which keeps its buying team sharp on competitive accounts.

3. Nasmedia (나스미디어)

Nasmedia is Korea's largest independent digital media rep firm and the clear leader among buyers that are not tied to a conglomerate. The KOSDAQ-listed company (ticker 089600) handled more than ₩500 billion in annual media transactions as of 2023.

Its specialty is programmatic, performance display, and mobile advertising. Nasmedia operates its own demand-side platform and ad platforms, and it represents major portal and publisher inventory, including Naver. For advertisers focused on measurable performance rather than brand reach, Nasmedia is widely cited as the go-to independent buyer in the market. The combination of proprietary ad tech and direct publisher relationships is hard to replicate.

4. McCann Korea (맥켄코리아)

McCann Korea is part of McCann Worldgroup under IPG and one of the longest-standing global network agencies operating in Seoul. It offers integrated media planning and buying alongside creative services, and it appears consistently in agency directories as a leading media planning and buying firm in South Korea.

The agency's core strength is global-network coordination. Multinational brands entering or scaling in Korea use McCann to bridge headquarters media strategy with local market execution, and the agency's deep local media relationships support that work. For brands that need a single agency to handle both creative and media across borders, McCann remains a reliable choice.

5. Dentsu Korea (덴츠코리아)

Dentsu Korea brings the Japanese group's global media brands, Carat and dentsu X, into the Korean market. The Seoul operation offers data-driven media planning, programmatic buying, and integrated communications for both Korean and multinational advertisers.

Its differentiator is global media scale paired with advanced analytics. Cross-border campaign coordination is a routine part of the work here, and the group's buying tools give Korean clients access to international inventory and benchmarking data. Dentsu sits comfortably in the top tier of network agencies operating locally.

6. Innocean Worldwide (이노션)

Innocean is the in-house agency of Hyundai Motor Group, headquartered in Seoul, with a global network spanning more than 20 countries and annual billings above ₩1 trillion. It handles media planning and buying for Hyundai, Kia, and Genesis worldwide.

Automotive media is the agency's foundation, and it manages large-scale vehicle launch campaigns along with sports and sponsorship media placements. Innocean has grown into one of Korea's largest agency groups by revenue, and its global media operations continue to expand beyond the captive automotive budgets that built it.

7. AJ Marketing

AJ Marketing is a Seoul-based marketing and media agency that appears in 2026 rankings of top media buying agencies in South Korea, including curated agency directories. It provides media planning, buying, and digital campaign execution for local and international clients.

The agency's reputation rests on verified client feedback rather than conglomerate scale. Agency marketplaces highlight its review-driven standing, which matters for advertisers who want accountable, hands-on service from a mid-sized shop. It is a practical option for brands that find the big network agencies too costly or too slow.

8. Saebyeok Naesi Corp (새벽내시)

Saebyeok Naesi is a Korean media planning and buying firm that appears in 2026 agency directory rankings for South Korea. The company focuses on media strategy and buying execution for advertisers targeting Korean audiences.

Its inclusion in curated 2026 lists reflects growing recognition among agency marketplaces rather than headline billings. For advertisers exploring specialist Korean-language media buying outside the major networks, Saebyeok Naesi is an emerging name worth evaluating.

9. JnJ Interactive Co., Ltd (제이앤제이인터랙티브)

JnJ Interactive is a Korean digital and interactive media agency cited in 2026 South Korea media buying rankings. It specializes in digital media planning, buying, and interactive campaign execution.

The agency serves advertisers seeking performance-oriented digital placements, and its focus on interactive formats positions it for campaigns built around engagement rather than pure reach. It is a recognized specialist in the 2026 agency listings, particularly for digital-first briefs.

10. Korcom Porter Novelli (코컴포터노벨리)

Korcom Porter Novelli is a Seoul-based communications and digital media marketing agency, part of the global Porter Novelli network. It provides media planning, digital marketing, and integrated communications services.

The agency appears in 2026 rankings of top digital media marketing agencies in South Korea, and its network affiliation gives it access to international communications resources. For brands that want media buying tied closely to public relations and integrated communications, Korcom Porter Novelli offers a combined approach that pure buying shops do not.

The right agency depends on what an advertiser needs. Brands with large budgets and broad reach requirements should start with the chaebol-affiliated giants, Cheil and HS Ad, which offer unmatched inventory access. Performance-focused digital advertisers will find better value and sharper measurement at Nasmedia. Multinational brands entering Korea typically benefit from the global coordination that McCann and Dentsu provide. Smaller advertisers and those testing the market can look to the specialist shops in the second half of this list, where service is more hands-on and pricing more flexible.