Population - 72,495
Area - 9.59 km2 (3.70 sq mi)
The Phaya Thai district was set up in 1966 taking areas that were part of Dusit and Bang Kapi districts. It was named after Phaya Thai Road, a major road in the area. Since then, many changes to the district has been made. In 1973, the Huai Khwang district was separated from Phaya Thai. Later in 1978, as an effort to balance the population among districts, the boundaries between Phaya Thai, Huai Khwang, and Bang Kapi districts were modified. A new Ratchathewi district was created, carving out the southern part of Phaya Thai in 1989. Finally in 1993, some eastern part were moved out of the district to the newly formed Din Daeng, leaving Phaya Thai with only one remaining sub-district, Sam Sen Nai as of today.
Note that, due to the split out of Ratchathewi, Phaya Thai Road is no longer in Phaya Thai district. It only runs through Ratchathewi and Pathum Wan. Similarly, Phaya Thai BTS Station is located in Ratchathewi, on Phaya Thai Road.
A large portion of the district on the east side is occupied by Royal Thai Army. This includes Army stadium, and military owned TV Channel 5. Several other government offices are also located here, such as Government Savings Bank , Ministry of Finance, and Ministry of Natural Resources and Environment.
The population is more concentrated in the area called Saphan Khwai (Thai: สะพานควาย) with many shops, apartments, and a BigC shopping center.
The Thai Philatelic Museum is recently renovated and moved to the building behind the Samsen Nai post office at Saphan Khwai in December 2004. Rather small, among of the exhibits are awards Thai philatelists received from various international competitions together with photocopies of the winning entries, posters depicting rare Thai stamps, winning postage stamp designs. It opens to public on Wednesday through Sunday except holidays.
Wat Phai Tan is the only Buddhist temple in the district.