Do you mean "best" as in largest / most valuable (by revenue, market share and global reach)? If so, the most-cited, authoritative ranking is Rabobank’s annual Global Dairy Top 20 (Aug 2024). Below I give the leading global dairy companies (ranked by dairy revenue), with a short note on each.

Top global dairy companies (Rabobank Global Dairy Top 20, 2024)

1. Lactalis (France) — world’s largest dairy group (President, Parmalat, Galbani, etc.). (research.rabobank.com, reuters.com)
2. Nestlé (Switzerland) — very large dairy & infant‑nutrition business (Nido, Carnation, Nesquik). (research.rabobank.com)
3. Dairy Farmers of America (USA) — major US farmer cooperative and processor. (research.rabobank.com)
4. Danone (France) — large global yogurt/infant‑nutrition/medical nutrition portfolio (Activia, Actimel, Aptamil). (research.rabobank.com)
5. Inner Mongolia Yili (China) — Asia’s largest dairy company and a global top‑five player. (research.rabobank.com, yili.com)
6. Fonterra (New Zealand) — major NZ farmer cooperative; big in ingredients/powders and exports. (research.rabobank.com)
7. Arla Foods (Denmark) — large European cooperative (Lurpak, Arla brand). (research.rabobank.com)
8. Royal FrieslandCampina (Netherlands) — major European cooperative (Friso, Campina). (research.rabobank.com)
9. Mengniu (China) — one of China’s top dairy processors and brands. (research.rabobank.com)
10. Saputo (Canada) — global cheese and dairy processor with strong North American presence. (research.rabobank.com)

Other notable global players (also in Rabobank’s Top 20): Amul (India’s giant cooperative), Unilever (dairy/ice‑cream exposure via spreads and ice cream businesses historically), Schreiber Foods, Savencia, Müller, Grupo LALA, DMK, Agropur and others. (research.rabobank.com)

Quick notes to help interpret “best”

• Source and definition: Rabobank’s Global Dairy Top 20 ranks companies by dairy-related revenue and is widely used as the industry benchmark. Rankings shift year-to-year with commodity prices, exchange rates and M&A. (research.rabobank.com, rabobank.co.nz)
• Cooperatives vs multinationals: Several of the largest dairy names are farmer cooperatives (Dairy Farmers of America, Fonterra, Arla, FrieslandCampina, Amul) — they operate differently from investor‑owned multinationals (Lactalis, Nestlé, Danone). (research.rabobank.com, ft.com)
• Regional leaders: Yili and Mengniu dominate China; Amul dominates India’s domestic market (Amul is a very large cooperative with extensive farmer membership and rapidly expanding exports). (yili.com, ft.com)

If you’d like, I can:

• Give the full Rabobank Top 20 list and revenues (2023/2024 figures).
• Provide a “best by category” list (e.g., best for cheese, yogurt, infant formula, sustainability/ESG, or best regional brands in the U.S., EU, China, India).
• Compare company size (revenue, market cap) or show recent M&A and outlook.

Which follow-up would you prefer?