Offshore renewable energy resources are options to address a country's energy and climate objectives without having to occupy vast amount of land space. Offshore wind power production, among the various offshore renewable options, has gained popularity albeit its dependence on the deployment location's wind conditions, technical challenge in construction and grid connection, and potentially high capital cost. The wind conditions in Southeast Asia are generally much less favourable as compared to other parts of the world, but several economies in this region consider offshore wind energy as a long term solution to decarbonize the electricity sector and to diversify the source of electricity. There is thus a need to evaluate the true benefits of offshore wind energy under the region's suboptimal climatic conditions. In response, this study employs the life cycle analysis approach to conduct a cost-benefit analysis of offshore wind energy in the context of Southeast Asia. Findings from study suggest that the cost of offshore wind energy remains high at the moment for Southeast Asia. The findings further contribute to the debate on offshore wind energy by setting the bottom-line for deployment under unfavourable climatic conditions in the tropical region and world-wide. However, offshore wind farm could still represent a plausible option through technology innovation in wind turbine designs and reductions in the cost of wind turbine and submarine power cable. As suggested in this study, there is potential for the cost of offshore wind energy to reach parity against onshore renewables such as solar energy in the context of Southeast Asia.