Bang Lamphu Lang (Thai: บางลำภูล่าง, pronounced [bāːŋ lām.pʰūː lâːŋ]) is a khwaeng (subdistrict) of Khlong San district, Bangkok's Thonburi side (west bank of Chao Phraya river).

Its name "Bang Lamphu Lang" meaning "lower place of mangrove apples".

Its name has a similar origin to Bang Lamphu in Phra Nakhon side (ฺBangkok core).

Today, alike to Bang Lamphu, although mangrove apples and fireflies have disappeared, but its name is still used for this area.

Bang Lamphu Lang (including other areas of Khlong San) in the past was the location of many large businesses, such as salt warehouse, fish sauce factory, wheat flour mill, saw mill and tannery.