Pathum Wan is one of the fifty districts (khet) of Bangkok, Thailand. It lies just beyond the old city boundary of Khlong Phadung Krung Kasem, and was a rural area on the eastern outskirts of the city when royal villas were built there in the late nineteenth century. The district was officially established in 1915, and covers an area of 8.37 square kilometres (3.23 sq mi). A large part of the district area is taken up by the campus of Chulalongkorn University and the green expanses of Lumphini Park and the Royal Bangkok Sports Club. By the turn of the 20th–21st centuries, the district had become known as the modern-day city centre, home to the prominent shopping areas of Siam and Ratchaprasong.

The campus of Chulalongkorn University in Bangkok occupies an area of 637 rai in the city centre's Pathum Wan District. It accounts for just over half of the 1,153 rai of land owned by the university, the rest of which is commercially developed or used by other institutions. The campus sits on what was originally royal land surrounding Windsor Palace, granted for the university's use at its foundation in 1917 by King Vajiravudh. Ownership of the land was transferred to the university by an Act of Parliament in 1939.