Phra Pradaeng (Thai: พระประแดง, pronounced [pʰráʔ prā.dɛ̄ːŋ]) is a district (amphoe) of Samut Prakan province in Thailand.

Phra Pradeang was the original center of the area south of Bangkok near the mouth of the Chao Phraya River.

In 1815, King Rama II built the Pom Phlaeng Faifa Fort at the river's bend.

Due to economic problems in the early-1930s, several administrative entities were abolished, including Phra Phradaeng Province, which had its districts assigned to Samut Prakan and Thonburi effective 1 April 1932.

Operated by a private company, the motorised trams connected with motorboat services to Bangkok and to Paknam at each end of the line.