The combustion of fossil fuels primarily provides the energy supply in Sri Lanka. The energy generation in Sri Lanka is primarily realized by the combustion of thermal energy such as diesel and coal. The second energy generation source is Hydroelectricity. In 2016, Sri Lanka supplied an average of 67% of the total energy demand using fossil fuels such as thermal oil and thermal coal (100% imported); and 33% with renewable energy (30% hydro and 3% non-conventional, renewable energy), even though there are enough available renewable resources such as solar, wind and biomass, to supply all the energy required. Sri Lanka should begin to utilize the above renewable energy resources more effectively and abundantly as fossil fuel prices increase and deplete; and their effects of global warming worsen. Sri Lanka aims to achieve 100% electricity generation from high-quality renewable energy resources (100RE) by 2050. When meeting this target, the use of solar, biomass, wind, ocean energy and energy recovery from waste technologies are expected to play a significant role. The increasing use of renewable energy technologies will be of help with the solution of energy-related current environmental and socioeconomic problems and will assist in sustainable development. This paper reviews the available potential resources, the status of renewable energy technologies and market status in Sri Lanka by considering Sri Lanka's present energy status and the future energy mix towards 100RE.