Siam Square (Thai: สยามสแควร์) is Bangkok's main shopping drag and its BTS Skytrain station is often considered as the center of the city. This article expands the area to include Ratchaprasong, Ploenchit Road, Hualamphong Train Station and Chulalongkorn University.

While Rattanakosin represents Thailand's history and culture, Siam Square represents Thailand as a newly industrializing economy. Siam Square's first buildings were only constructed in the 1970s, on land of Chulalongkorn University which tried to get some extra rental income for the university. It started with ordinary shops, but has nowadays expanded to a shopping and entertainment mecca that has everything upper-class teenagers and college students could possibly want — luxury shopping malls and glitzy department stores filled with designer labels and hip fashion boutiques.

Despite the name, it is not a square in the traditional sense. It could better be described as a warren of small sois filled with hundreds of tiny boutiques, restaurants, cafes, record stores and bookshops, mostly catering to upper-class Thais, shopping-spree Malaysians, and working ex-pats. If you're not up for a trip to the Gap or a pink martini, it's still worth a visit just to see the Bangkok-of-the-future. The area north of Rama I Road does feature some kind of courtyard, but this could only be seen as an entry point for the Siam Center, Siam Discovery Center and Siam Paragon shopping malls.

Going east on Rama I Road, the shopping experience goes on at Ratchaprasong, an area which received worldwide fame when red shirt political protesters set up their camp here in May 2010. It is home to CentralWorld Plaza, the largest shopping mall in Thailand, which was set on fire during these protests and is still in the process of reconstruction. Some shops continue east along Ploenchit Road, but it gets more quiet as it goes east and is mostly home to some foreign embassies and airline offices.