As a component of public resources and national wealth, mines play a vital role in the economic development of nations, and their exploitation has always been subject to specific financial and legal regulations. In most legal systems, governments collect payments from operators, known as government royalties, the calculation of which may be based on the volume or weight of the extracted mineral, its market value, the operator’s profit, or a combination of these methods. The conceptual evolution of this institution in Iranian law—marked by the legal definition’s shift from “government revenue” in the 1998 Mining Law to “government’s share” in the 2011 amendment—has transformed its nature from a tax-like financial levy to one more akin to an inherent proprietary right. In Iran, pursuant to Articles 44 and 45 of the Constitution and the Mining Law, the right to exploit mines is granted to persons or entities by the Ministry of Industry, Mine, and Trade through a public tender and the issuance of an exploitation license. The licensee is then obligated to pay a percentage of the mineral’s value, as stipulated in the license and calculated at market rates, under the title of government royalties. Using a descriptive-analytical method and drawing on legal statutes and Islamic jurisprudential (fiqh) texts, this article seeks to answer the question: What is the legal nature of government mining royalties in Iran’s legal system, and what are its fundamental distinctions from similar concepts in public finance law? To this end, the study analyzes the concept and status of these royalties, distinguishing them from institutions such as taxes, duties, rent, ground rent (haqq al-ard), and Khums. It also examines the legal framework through which exploitation rights are granted. The findings indicate that government royalties constitute a legal institution distinct from other financial instruments. Its essence lies in the exploitation of public wealth under an innominate administrative contract, for which consideration is paid to the state. Although the law stipulates that these royalties should be determined based on the specific conditions of each mine (such as reserve size, extraction method, and profitability), in practice, there is a tendency to apply uniform rates, a practice that diverges from the legislator’s intent. Revising the mechanism for determining these royalties based on the specific conditions of each mine and the operator’s profit would lead to greater transparency, attract investment, and better realize the objectives of distributive justice.