Si Lom Road is a major street in the Thai capital Bangkok, best known for its commercial neighbourhood, which, along with the nearby and roughly parallel Sathon Road, forms one of the city's main business districts. It runs in a southwest–northeast direction between Charoen Krung and Rama IV roads in the city's Bang Rak District, forming the boundary between Suriyawong Subdistrict to its north and Si Lom Subdistrict to its south. Si Lom was one of the earliest modern roads to be built in the city, and some of its side streets serve historic ethnic neighbourhoods from the late nineteenth century, while others are known as shopping and nightlife venues.

Bangkok, officially known in Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies 1,568.7 square kilometres (605.7 sq mi) in the Chao Phraya River delta in central Thailand and has an estimated population of 9.0 million as of 2021, 13% of the country's population. Over 17.4 million people (25%) lived within the surrounding Bangkok Metropolitan Region at the 2021 estimate, making Bangkok an extreme primate city, dwarfing Thailand's other urban centres in both size and importance to the national economy.