'The Great happiness') is a district (srok) located in Kampong Cham province, Cambodia.

Srey Santhor is in south western Kampong Cham and lies on the border with Kandal and Prey Veng provinces.

Between July and November 2000, Cambodia was subject to catastrophic flooding in all provinces bordering the Mekong River.

However, in 2000 90% of the land area in the district was flooded and 95% of the annual rice crop was completely destroyed.

To the south are Sithor Kandal and Pea Reang districts of Prey Veng province.