This study presents a systematic literature review to identify the major research gaps in the literature related to the studies of strategic planning on competitive advantage. The study employed a systematic review of the literature contained in three databases, Google-Scholar, ERIC and Semantic-Scholar. The analysis of the literature in this study revealed that there is an increase in the number of studies focusing on the relationship between strategic planning and competitive advantage. The systematic review of the literature indicates a wider gap in the existing research in that: there are very few studies that include continuous variables to gain a deeper understanding of the relationship between strategic planning and competitive advantage; there are very few countries that have conducted these studies in relation to the relationship between strategic planning and competitive advantage; the research methodologies employed in the studies reviewed were mainly quantitative; and there are other sectors that have received little or no attention in the focus area. The study included only peer-reviewed, English-language literature. A key contribution of this study is that the steps, methodology and analysis used can be replicated and applied by scholars to conduct similar or even different studies to identify gaps in the literature review.