The growing demand for clean, sustainable, and viable energy in the twenty-first century prompted researchers to focus their efforts on developing renewable-based technologies. In that context, hydropower energy can be one of the feasible alternatives to meet future energy demands. It has been observed that at reservoir dams, the breakdown of flooded biomass and organic matter produces a significant amount of Green House Gas (GHG), which contributes to global warming. Small-scale hydro-based technologies produces GHG emissions when compared to dam hydropower since they produce most of their emissions during the building and maintenance phases. Small-scale hydro-based technologies such as hydrokinetics can be considered one of the preferable options, which generate energy from flowing water. A complete review of harnessing the power from flowing water by hydrokinetic turbines (HKTs) has been carried out in this article. Information regarding the state of the art and current status of cutting-edge technology has been gathered with the working principles of hydrokinetic turbines, classifications of HKTs and their applications, the terminology used for HKTs, the dam’s impact on the environment, and the selection of turbines, have been discussed thoroughly in this study. Furthermore, a detailed discussion of the design parameters of HKTs like solidity, power coefficient, Tip Speed Ratio (TSR), angle of attack, number of blades, type of blades, performance curve, Reynolds number, aspect ratio, blockage, augmentation and rotor mounting have been included. These parameters will aid in selecting HKT for a given environment condition. A comparison between the wind turbine and the hydrokinetic turbine has also been added. It has been observed that Micro Hydro River (MHR) technology is undergoing continuous R&D as compared to other rural electrification technologies. Various government policies, contemporary civilization, industrialization, and a standard way of life are also important factors that affect the use of HKTs as energy-harnessing devices.