Sri Lanka Railways S9 is a class of diesel-electric multiple unit (DEMU) train sets operated by Sri Lanka's state run rail operator, Sri Lanka Railways.

[1] The Class S9 DEMU was introduced to Sri Lanka in the year 2000.

They were built by the China South Locomotive & Rolling Stock Corporation, and are the first class of Diesel-electric multiple units to run on Sri Lankan rails.

The Class S9 only has Third class accommodations as it is used exclusively for commuter services.

The length of one car is 19.81 metres (65.0 ft).