It is bounded by other Bangkok districts (from north clockwise): Bueng Kum, Saphan Sung, Prawet, Suan Luang, Huai Khwang, Wang Thonglang, and Lat Phrao.

Bang is a common prefix for place names in Thailand and roughly means a "hamlet by the waterfront".

Lastly, it could also come from kapiyoh (กะปิเยาะห์), the Thai word for a type of cap worn by Islamic men (taqiyah), as many Muslims settled in the area.

As it grew into a larger town, Bang Kapi was made an amphoe (district) of Phra Nakhon province.

The missing numbers 2, 3, 4, 5, 6 and 7 belong to the sub-districts which were split off to form Wang Thonglang, Lat Phrao and Bueng Kum districts.