Si Lom (or Silom, Thai: สีลม windmill) is a sub-District and road in Bang Rak district, Bangkok, Thailand. Constructed in 1851 as part of a dyke and irrigation system, Silom road has become one of Bangkok's most cosmopolitan streets and major financial centre; it is the home to some of the largest companies in Thailand ex. The Charoen Phokphand Group (CP), Bangkok Bank PLC, as well as a number of insurance and securities firms, it is often dubbed the "Wall Street of Thailand". Silom offers quite a broad range of nighttime activities ranging from street side shopping to strip dancing show; both Patpong and Thanon Thaniya (Little Tokyo) having entrances from Si Lom Road.
Furthermore, it has a popular gay area. Soi 2 has several gay lounges and club, DJ Station. This very small side street, packed between the buildings, has a passport check. As well, soi 4 is popular among gays for its terraces.
Si Lom Road runs parallel to the Sathorn business district along Sathon Road. This close proximity between two major thoroughfares has led to serious traffic congestion in the area.
Si Lom is also the name of an MRT Blue Line subway system stop at the intersection between Si Lom, Ratchadamri and Rama IV Road. It connects with the Sala Daeng Station of the BTS Skytrain, which is also titled Silom Line.
The colourful Mariamman Temple, Bangkok, also known as Wat Khaek, is located in Si Lom.