"Japanese McDonald's: 10/10. Give these guys a Michelin star," the 39-year-old said on Facebook and Instagram, alongside photos of himself in sunglasses eating a burger and of his wife Priscilla Chan outside the golden arches.
Seen on Zuckerberg's packed tray were popular Japanese menu items including a shrimp-patty burger, a teriyaki chicken burger, edamame bean salad and bite-sized churros -- along with the more usual chicken nuggets and fries.
Zuckerberg was in Japan with his family for a trip mixing pleasure -- including skiing and making Japanese swords -- and business.
After reportedly meeting with Facebook developers in Tokyo on Monday and Tuesday, Zuckerberg was set to travel to South Korea and then India for the wedding of a billionaire's son.
In Seoul Zuckerberg is expected to hold meetings with President Yoon Suk Yeol and leaders of tech titans Samsung and LG, according to South Korean media.
He will also meet the CEO of LG Electronics to discuss the development of a mixed-reality headset to compete with Apple's Vision Pro, the Korea Economic Daily reported.
In Gujarat in India, Zuckerberg will attend the March 1-3 pre-wedding celebrations of the son of Mukesh Ambani, chairman of oil-to-telecoms giant Reliance Industries, reports said.
Meta, Google and others have invested billions of dollars in Reliance's digital unit Jio Platforms as it seeks to take on Amazon and Walmart in India's vast e-commerce market.