The Don Mueang–Suvarnabhumi–U-Tapao high-speed rail (HSR) in Thailand is expected to be operational in 2029. Also known as the High-Speed Rail Linking Three Airports Project, this is one of the key developments under the Eastern Economic Corridor (EEC) of Thailand. The Charoen Pokphand Group (CP) led consortium, comprising Bangkok Expressway and Metro Public Limited Company (BEM), China Railway Construction Corporation Limited (CRCC), CH. Karnchang Public Company Limited, and Italian-Thai Development Public Company Limited, will build the THB224.5 billion rail line.

The consortium will also operate the system for a period of 50 years, after which it will be transferred to the state.

The 220-km-long HSR line will have 9 stations and will be based on the existing airport rail link (ARL) and State Railway of Thailand (SRT) routes, along Bangkok, Samut Prakan, Chon Buri, Rayong and Chachoengsao. Once operational, the line is expected to receive an average footfall of 147,000 passengers per day. Trains will have a maximum operating speed of 250 km/hr. Additionally, there are also plans to develop smart cities along the HSR route.