Oil and gas (O&G) companies are progressively developing and adopting sustainability strategies in response to regulatory and market pressures embedded in the energy transition process. The UN’s Sustainability Development Goals (SDGs) are strongly linked to energy transitions and key to achieving successful sustainability strategies. A novel analytical framework to evaluate sustainability strategies is proposed and applied to the case study of Petronor, a refining company in the Basque Country (Muskiz, Bizkaia). The analysis helps to assess how O&G companies contribute to the energy transition by focusing on the SDGs. This first application of this framework suggests that a comprehensive understanding of an O&G company’s sustainability efforts is needed to fully evaluate its role in the energy transition.