Koh Si Chang is a small elongated island off the coast of Chonburi, on the Eastern Seaboard of Thailand, which is less visited than many of the other islands in the region.

Yet, it has many places of interest, such as the Buddhist temple Wat Chuthathittham Sapha-ram Worawihaan (fig.), Sahn Chao Pho Khao Yai (fig.), a former Summer Palace of King Rama V (fig.), and Sapaan Atsadaang Jetty (fig.), among others.

It has only a handful of residents and few tourists, making for a very relaxed atmosphere with quiet sandy beaches and scenic coastal roads.

The island can only be reached by ferry, with a regular boat service departing from Sri Racha on the mainland.