KTM Komuter is an electrified commuter train service first introduced in 1995, catering especially to commuters in Kuala Lumpur and the surrounding suburban areas. KTMB provides 248 commuter services daily, serving 45 stations along 175 route-kilometres. The network consists of three lines: Rawang-Seremban Route, Sentul-Port Klang Route and the Rawang-Kuala Kubu Bharu shuttle route. Trains on the two lines run at 15 minutes frequency during peak hours and 20 minutes frequency during off-peak hours. The Rawang-Kuala Kubu Bharu shuttle services operates at half hour frequency. Komuter coaches are currently the most modern in the KTM fleet and are air-conditioned.
KTM Komuter is a heavily utilised mode of transportation by commuters working in Kuala Lumpur as the service is an alternative for road travel, which is occasionally hampered by congestion. Virtually all KTM Komuter stops offer "Park & Ride" parking lots for those who drive to and from the station or halt. KTM Komuter ridership is estimated to be about 34.97 million passengers in 2006.
KTM Komuter is currently the most profitable passenger service offered by KTMB, contributing RM84.63 million to group revenue in 2006, higher than KTM Intercity's profit of RM70.94 million in the same year.