1. WPP (UK)

Headquarters: London, UK

Why it stands out:
World's largest advertising and PR group by revenue
Owns major agencies like Ogilvy, Wunderman Thompson, VML, and GroupM

Specialties:
Creative advertising, digital marketing, PR, media planning, branding

Brands/Clients:
Unilever, Coca-Cola, Ford, Nestlé, HSBC

2. Omnicom Group (USA)

Headquarters: New York, USA

Why it stands out:
Owns well-known networks like BBDO, DDB Worldwide, and TBWA

Specialties:
Integrated marketing, media planning, branding, data-driven strategies

Brands/Clients:
McDonald’s, Apple, PepsiCo, Volkswagen, Visa

3. Publicis Groupe (France)

Headquarters: Paris, France

Why it stands out:
Strong in digital transformation and data-driven marketing
Owns Publicis Worldwide, Saatchi & Saatchi, Leo Burnett, Sapient, and Epsilon

Specialties:
Creative services, digital transformation, performance marketing

Brands/Clients:
Heineken, Renault, L’Oréal, Nestlé, Samsung

4. Interpublic Group (IPG) (USA)

Headquarters: New York, USA

Why it stands out:
Emphasis on data, consumer insights, and multicultural marketing
Owns agencies like McCann, FCB, MullenLowe, and R/GA

Specialties:
Advertising, digital marketing, PR, and experiential marketing

Brands/Clients:
Microsoft, Coca-Cola, Spotify, General Motors, Mastercard

5. Dentsu (Japan)

Headquarters: Tokyo, Japan

Why it stands out:
Asia’s largest advertising group, rapidly expanding globally
Owns Dentsu Creative, Isobar, Carat, and Merkle

Specialties:
Digital innovation, performance marketing, customer experience

Brands/Clients:
Toyota, Canon, Shiseido, Sony, American Express