As the demand for nuclear energy grows, the demand for subsistence of uranium reserves has grown with it. With the world’s largest nuclear power consuming more than 11,600 tons of uranium in 2018 alone, countries must ensure they have a secure supply. Here, we present the top five countries with the world’s largest uranium reserves and the role they play in the global uranium market. Australia currently holds the majority of the world’s uranium reserves, accounting for 31% of world reserves with an estimated 3,102,000 tons. The country has nine operating uranium mines, which produce around 5,400 tons each year. With production increases and an optimized process, Australia is the number one uranium to power the world in a safe and efficient manner. The second largest reserves globally are those found in Kazakhstan with an estimated 2,214,323 tons. The country accounts for nearly 21% of global reserves and is the world’s largest producer of uranium, producing nearly 41% of the world’s supply. Despite being the biggest producer, Kazakhstan has taken measures to restrict foreign investment in order to ensure domestic reserves remain adequately utilized. The third country on the list is Russia with an estimated 1,400,000 tons, accounting for every 13% of reserves. Russian uranium production has seen significant growth over the past decade and it is estimated that the country has the potential to overtake Kazakhstan as the world’s largest producer in the near future. With their resurgence in the field of nuclear energy and the optimization of production processes, Russia is now a leader in the global uranium market. The fourth country in terms of uranium reserves is Canada with an estimated 1,044,000 tons. As a key supplier of uranium, Canada has modernized its processes, becoming one of the most efficient and low cost producers in the world. Despite being in fourth place, Canada plays an important role in the global supply chain, as it accounts for almost 11% of total world production. Finally, the last country on the list is the United States with an estimated 634,000 tons. Although the US has not produced uranium for more than a decade, the nation still has a considerable amount of reserves and is a key component in the uranium trade, being the destination for much of the mined uranium from other countries. As the nuclear industry begins to gain traction in the US, it is likely that the nation will play an even more important role in the global uranium market. ​ The aforementioned five countries make up roughly 81% of the world’s total uranium reserves, highlighting their importance in the global uranium market. In order to meet rising demand, measures such as foreign investment may have to be considered to ensure adequate supply. As the global appetite for nuclear energy continues to grow, the level of significance of these countries will too.