Phnom Chisor, Archaeological site in Samraŏng District, Cambodia.

Phnom Chisor is a temple complex situated on a hill in the Cambodian countryside south of Phnom Penh, consisting of multiple structures. The site features laterite walls and sandstone elements with detailed carvings, and includes an ancient water reservoir.

Suryavarman I, who ruled 1002–1050, built the temple on the hill and dedicated it to Shiva, partly to Vishnu. Inscriptions name the site Sri Suryaparvata, "Mountain of Surya", and record an offering there in 1019. A second inscription traces the ancestry of Suryavarman II to Harshavarman. The nearby Mekong Delta, cradle of Funan and Chenla, likely motivated the king to assert control over the region.

The temple's original Sanskrit name, Sri Suryaparvata, means "Mountain of Surya," after King Suryavarman I, who also tolerated local Vishnu cults. Two inscriptions remain: one records offerings to the mountain deity in 1019, the other traces Suryavarman II's royal lineage. Today the site is a Buddhist pilgrimage place, and Brahmans still consider the nearby Tonle Om lake sacred for ritual bathing.

Reaching the temple requires climbing many steps to the top, so sturdy footwear is advisable. Bring your own water and snacks, as facilities on site are limited.

The baray east of the temple is called Tonle Om, and Brahman pilgrims considered its water able to wash away sins. A stairway built in the temple's founding era links the sanctuary to Sen Chhmos, Sen Phouvang and the lake. Bombing in the 1970s sealed the nearby Rung Vimean Chan cave with large rocks.