Illegal mining is mining activity that is undertaken without state permission, in particular in absence of land rights, mining licenses, and exploration or mineral transportation permits. It can be a subsistence activity, as is the case with artisanal mining, or it can belong to large-scale organized crime, spearheaded by illegal mining syndicates. Illegal mining and trafficking in precious metals negatively impact peace, stability, security, development, governance, the rule of law, the environment, and the economy. Furthermore, illegal mining of precious metals is often accompanied by serious human rights abuses and can have severe environmental impacts, including through deforestation, land degradation, and pollution. Illegal mining and trafficking of precious metals are often linked to economic crimes such as tax evasion, fraud, and corruption, by exploiting loopholes in regulatory frameworks. Some of the most common illegally mined materials are gold and diamonds.

In summary, illegal mining is the act of mining without proper authorization from the state, and it can have negative impacts on various aspects of society, including the environment, human rights, and the economy.