In the thesis, I aim to address the following questions: 1) Are Qatar and Algeria classified as rentier states, and what factors contribute to this classification? and 2) How are these countries adapting to the energy transition? To achieve this goal, the thesis will draw upon literature from scientific journals, articles and data from international economic organizations, to provide a comprehensive macroeconomic analysis, along with an exploration of the Rentier State Theory (RST) and energy transition. This analysis will highlight how these concepts can be implemented in the selected states. This thesis aims to foster a new dialogue regarding the economies of MENA countries, particularly in relation to their responses to energy transition and the measures imposed by the international community to address issues like the climate change. Additionally, this thesis will encompass both theoretical and quantitative analyses, providing an in-depth examination of the core themes.