Sarath Ratanavadi

Sarath Ratanavadi (, ) is a Thai engineer and billionaire businessman who is the founder and chief executive officer of Gulf Development, which operates in sectors such as power generation, telecommunications, and digital infrastructure. He is often referred to as Thailand's "energy king".

As of 2026, Ratanavadi's net worth was estimated at around US$16 billion.

Early life and education Sarath Ratanavadi was born in Bangkok on July 12, 1965, into a military family. His father, General Thavorn Ratanavadi, served as chief of staff of the Royal Thai Armed Forces, and his grandfather, Sod, was a member of the 1932 People’s Party revolutionary movement. These companies were later merged to create Gulf Energy Development Company Limited in 2007 as the holding company. During his tenure, the Gulf group grew into one of Thailand’s major independent power producers, with power plants across Thailand and Southeast Asia reaching a combined capacity of over 12,000 MW by the 2020s.

In 2022, Ratanavadi opened Stonehill, a private golf club in Thailand. The course spans more than 340 acres and was designed by the well-known golf course architect Kyle Phillips.

In 2025, Ratanavadi merged Gulf Energy Development with Intouch Holdings to form Gulf Development, valued at $25 billion. That same year, Gulf expanded its operations into finance and acquired a stake in Kasikornbank, the third-largest bank of Thailand.

Philanthropy Ratanavadi has supported numerous charitable initiatives in healthcare and community development. In 2015, he donated $3 million to the USC golf program. Following the donation, his son was admitted to the university as a walk-on golfer, prompting donor-influence and conflicts-of-interest investigation. Ratanavadi also serves on USC’s Board of Councilors of the Annenberg School for Communication and Journalism.

Personal life Sarath Ratanavadi is married to Nalinee Tantisoonthorn.