Nigeria, like many other regions globally, faces challenges with groundwater contamination, particularly from toxic metal(loid)s such as lead (Pb), nickel (Ni), arsenic (As), and chromium (Cr). This chapter examined the sources, impacts, and removal techniques associated with Pb, Ni, As, and Cr contamination in Nigeria’s groundwater. It explored the geological, industrial, anthropogenic, and combined sources of these contaminants, their detrimental effects on human health and the environment, and various methods employed for their removal. It also explored the relationships between contamination sources and remediation techniques specific to Nigeria, emphasizing the need for tailored solutions. The novelty lies in providing insights into the unique challenges and opportunities for managing heavy metal contamination in Nigerian groundwater systems. These toxic elements in Nigerian groundwater pose significant health and ecological risks to the human and aquatic populations due to their bioaccumulation potential; and thus, demand effective mitigation strategies. Geological and environmental factors contribute to the metal(loid)s pollution in Nigeria, impacting both shallow and deep aquifers. Tracing and tracking these pollutants in Nigerian groundwater is very crucial for understanding the contamination sources and implementing remediation strategies effectively. The remediation of these heavy metal(loid)s in Nigeria employs physicochemical, biological, and hybrid methods. Several challenges were identified and highlighted in this chapter. Understanding these issues and challenges, policymakers, researchers, and stakeholders can develop informed strategies to safeguard water resources and protect public health in the country.