Strategic planning positively affects the performance of state-owned companies (SOEs) in Kenya, with evidence indicating that their effective application enhances organizational outcomes. However, despite the adoption of strategic planning frameworks, many State-Owned Enterprises in Kenya continue to experience performance challenges such as inefficiency, weak governance structures, financial mismanagement, and delays in project implementation. These issues have led to low productivity, dependence on government bailouts, and failure to meet performance targets. This persistent underperformance raises concerns about the effectiveness of strategic management practices within these entities. The objective of this study was to examine the influence of Strategic planning on the organizational performance of State Corporations in Kenya: a case study of the Geothermal Development Company. This research was anchored by the Resource-Based View Theory, and supported by Strategyas-Practice (SAP). Employing a descriptive research approach, data from 871 employees at Geothermal Development Company (GDC) were analysed employing a stratified sampling technique, resulting in a sample population of 274 respondents. A standardized questionnaire was employed to gather information, preceded by a pilot study to validate the tool's dependability. Analysis involved reviewing surveys, extracting statistics, and applying regression analysis via SPSS version 24 to explore how independent and dependent variables relate to one another. The study found that strategic planning was inclusive and systematic, featuring stakeholder engagement and goal prioritization. Effective strategy formulation was evidenced by personnel engagement and alignment with organizational objectives, promoting a link between goals and performance. The study recommends that Kenyan state corporations enhance strategic planning through better organization, stakeholder participation, and regular updates. It stresses the importance of developing analytical skills for data-driven decision-making and aligning planning with performance metrics. The research advocates for stakeholder engagement, measurable outcomes, and suggests longitudinal studies to explore causal relationships.