"By putting local businesses at the heart of tourism, Quang Nam is proving sustainability starts at home," Wanderlust said.
Quang Nam's two UNESCO World Heritage Sites are the My Son Sanctuary, a Hindu sacred site of the ancient Champa Kingdom, and Hoi An Ancient Town.
In recent years, the province has started offering eco-friendly tours such as coracle basket boat tours in the Bay Mau nipa palm forest and a cycling tour of Tra Que Vegetable Village.
Tourism businesses have prioritized environmental sustainability, Wanderlust said.
Many luxury resorts and restaurants in Hoi An adopt a plastic-free policy, as they use organic materials and provide tourists with eco-friendly tourism products.
Quang Nam welcomed 1.63 million tourist arrivals in the first quarter of this year, a four-fold year-on-year increase, according to the provincial Department of Culture, Sports, and Tourism.
Of the total 765,000 were international travelers, up 85 times year-on-year.
The other three representatives in the list were Bhutan, Singapore and Ataúro Island in Timor-Leste.
Wanderlust said the list aims to honor tour operators and individuals who make commitments to protecting the green environment.