The environment naturally contains heavy metals (HMs); however, their indiscriminate usage for human needs has changed the geological cycles and biochemical equilibrium of these substances. Owing to their toxicity, prolonged environmental half-lives, and bioaccumulative properties, HMs are widely recognized as contaminants in the environment. Consequently, there is an overabundance of HMs being released into the environment, such as land and water bodies. These HMs include arsenic (As), chromium (Cr), cadmium (Cd), copper (Cu), mercury (Hg), cobalt (Co), nickel (Ni), selenium (Se), zinc (Zn), and lead (Pb). The natural sources of HMs primarily include rock weathering and eruption of volcanoes, whereas anthropogenic contributors include mining operations and countless industrialized actions along with agricultural activities. Long-term exposure to HMs and their increased deposition can be detrimental to aquatic life and human health. Moreover, HM contamination and toxicity of terrestrial and aquatic ecosystems pose a significant public health threat. However, the increasing quantity of waste generated by enterprises daily is a pressing issue behind the HM contamination and accumulation. Therefore, it is crucial to recognize the detrimental impact that HM contamination poses to this ecosystem and aquatic water bodies. This chapter explores the sources of HMs and contamination of HMs in different aquatic water bodies. A substantial section of the chapter focuses on the trophic transfer of HMs across several levels of the food chain, including fishes, microorganisms, soil to plants, invertebrates, mammals, and humans. This chapter also discusses the measurement of this trophic transfer and the impact of HMs on aquatic water bodies and human health.