Tha Sae (Thai: ท่าแซะ, pronounced [tʰâː sɛ́ʔ]) is a district (amphoe) in the northwestern part of Chumphon province, southern Thailand.

King Chulalongkorn downgraded Mueang Tha Sae to a district of Chumphon Province.

The district name originates from the public canal pier (in Thai: tha), where plenty of catechu trees (Callerya atropurpurea) grow.

The coffee-growing valley of Ban Panwal in the district includes 178,283 rai of robusta coffee plantations.

Local brands include Thamsing, ST Chumphon, and Khao Tha-Lu Chumporn.