In the rapidly evolving landscape of digital marketing, businesses are increasingly focusing on measuring the effectiveness of their strategies and evaluating the return on investment (ROI) to optimize their marketing efforts. This paper explores the critical metrics and methodologies used to assess digital marketing performance and ROI. Key performance indicators (KPIs) such as website traffic, social media engagement, email open rates, and paid advertising costs are examined for their role in providing actionable insights. The paper also delves into advanced ROI analysis techniques, including basic ROI calculations, customer lifetime value (CLV), and attribution models, to demonstrate how businesses can accurately measure the impact of their digital marketing investments. Through detailed case studies, this paper highlights practical applications of these metrics and analysis methods, showcasing their effectiveness in real-world scenarios. Challenges associated with digital marketing measurement, such as data accuracy and attribution complexities, are discussed, along with best practices for overcoming these obstacles. The findings underscore the importance of a comprehensive approach to digital marketing metrics and ROI analysis, providing businesses with the tools and insights necessary to enhance their marketing strategies and achieve sustainable growth. This paper contributes to a deeper understanding of how digital marketing metrics can be effectively used to drive decision-making and maximize marketing value.