This study aims to examine the effectiveness of the use of Search Engine Optimization (SEO) in digital marketing strategies through a comprehensive meta-analysis study. By collecting and analyzing data from previous studies involving SEO as a marketing tool, this study evaluated the extent to which SEO can improve online visibility, website traffic, and ultimately sales conversions. The results of a meta-analysis of 10 studies conducted between 2022 and 2024 show that the implementation of SEO is consistently associated with a significant increase in organic search rankings and website traffic with an effect size (d) value of 1.049 in the high effect size category. Further analysis revealed that variables such as content quality, keyword optimization, and backlinks have a significant influence on SEO effectiveness. This research provides empirical evidence that supports the implementation of SEO as a crucial component of digital marketing strategies, while also offering insights into best practices and factors that influence SEO success. With these results, practitioners and academics can better understand how SEO strategies can be optimized to achieve maximum results in an increasingly competitive digital environment.