The Sukhumvit Line is an elevated metro rail line of the BTS Skytrain in Bangkok, Thailand. From the central Siam Station, where it connects with the Silom Line, the line runs both northwards along Phaya Thai and Phahon Yothin Roads to Khu Khot in Lam Luk Ka District in Pathum Thani, and eastwards along Rama I, Phloen Chit and Sukhumvit Roads, through Bang Na District to Kheha Station in Samut Prakan. BTS daily ridership (2019) is 740,000 passengers per day.

The Bangkok Mass Transit System, commonly known as the BTS Skytrain, is an elevated rapid transit system in Bangkok, Thailand. It is operated by Bangkok Mass Transit System PCL (BTSC), a subsidiary of BTS Group Holdings, under a concession granted by the Bangkok Metropolitan Administration (BMA) which owns the lines. The system consists of 62 stations along three lines with a combined route length of 70.05 kilometers (43.53 mi). The BTS Sukhumvit Line runs northwards and south-eastwards, terminating at Khu Khot and Kheha respectively. The BTS Silom Line which serves Silom and Sathon Roads, the central business district of Bangkok, terminates at National Stadium and Bang Wa. The Gold Line people mover runs from Krung Thon Buri to Klong San and serves Iconsiam. The lines interchange at Siam station and Krung Thon Buri. The system is formally known as "The Elevated Train in Commemoration of HM the King's 6th Cycle Birthday".