Perera enrolled in the National Diploma in Technology (NDT) program at the Institute of Technology, University of Moratuwa before dropping out later to pursue his business ventures.
In 2013, Perera became Sri Lanka's wealthiest individual, with a net worth of LKR 70 billion ($538 million); he owns one of 50 limited edition Bentley Mulsanne Hallmarks
Dhammika is the founding Chairman and Managing Director of Vallibel One Group, a holding company with investments in financial services, tile and sanitary ware manufacturing, and leisure sectors through its subsidiaries L B Finance PLC, Royal Ceramics Lanka PLC group and Greener Waters Ltd. It holds a 14.99% stake in Sampath Bank PLC. Dhammika Perera concurrently holds several other positions in both private and public sector. These include, Former Chairman of Sampath Bank PLC, Vallibel Finance PLC, Vallibel Power Erathna PLC, The Fortress Resorts PLC, The Queensbury Leisure Ltd and Delmege Limited; Deputy Chairman of Hayleys PLC, Royal Ceramics Lanka PLC, Horana Plantations PLC, Lanka Ceramic PLC and LB Finance PLC. He is on the boards of Amaya Leisure PLC, Haycarb PLC, Hayleys MGT Knitting Mills PLC, The Kingsbury PLC, Dipped Products PLC, Lanka Floortiles PLC.