Sustainable design approaches reduce energy consumption of urban form and the environment. Urban public space design is an efficient sustainable strategy to improve thermal and microclimatic conditions of outdoor spaces. A tropical city like Rajshahi, Bangladesh, an example of a rapid urbanization, is now dealing with the challenge of sustainable urban development, especially in the urban public space where thermal comfort makes a vital role for active to use of outdoor space in the various time. People’s activities and usages of outdoor space particularly urban public place which is the most viable and sustainable features of urban design is directly affected by thermal setting and thus affect people’s activities. This research aims to calculate the thermal comfort indices to find out the comfort condition of the urban public space by using a CFD based simulation software “ENVI-Met”. Online sources are used to collect site specific microclimatic data for thermal comfort. Data is then synthesized to find out MRT and thermal comfort condition. The aim is to develop and recommend a checklist of comfortable urban form and potential design and materials features to investigate the scope of improvement of outdoor thermal comfort of urban public space of study area. Both the physical (height width ratio of urban form, vegetation, water features, orientation, materials) has strong impact on improving thermal comfort and activities. This research suggests some urban design options for an effective and comfortable outdoor space in the context of tropical city like Rajshahi in the end.