Hydropower is among the most carbon-neutral energy sources, and Australia has significant untapped potential for mini hydropower generation, especially in regional and remote areas where decentralised energy solutions are in growing demand. Mini hydropower systems, typically generating up to 10 MW, offer a reliable, low-emission alternative by utilising existing infrastructure such as irrigation channels, water supply systems, and small rivers. This study presents a critical review of the technical feasibility (i.e., head), environmental advantages (i.e., emission reduction), and economic viability (i.e., levelized cost of electricity) of mini hydropower across Tasmania, Victoria, and New South Wales. Through an analysis of current projects, the paper evaluates system performance and grid integration challenges, including efficient renewable energy generation and seasonal water flow variability. It also discusses how advances in turbine design, modular systems, and digital controls enhance scalability and reduce costs, making mini-hydro more attractive for smaller communities and agricultural applications. As Australia moves toward net-zero emissions by 2050, mini hydropower offers a complementary solution that enhances energy resilience, supports decarbonization, and strengthens regional grid stability. This research summarizes a review of all potential benefits. Then, it identifies the major barriers such as regulatory hurdles, high capital costs, and limited awareness among stakeholders. Finally, recommendations are provided to overcome the barriers and accelerate the development through streamlined approvals, incentives, and cross-sector collaboration.