Whales, dolphins, sea turtles, sharks, and other marine megafauna are iconic species that capture global attention and play essential ecological roles. The study of marine megafauna: behavior and conservation explores their migratory patterns, feeding strategies, and social interactions while assessing threats that jeopardize survival. Industrial fishing, vessel strikes, pollution, and climate-driven habitat changes are among the greatest risks they face. Advances in satellite tagging, bioacoustic monitoring, and drone-based observation are providing unprecedented insights into movement and behavior, enabling evidence-based strategies for species protection. Conservation initiatives are increasingly integrating ecological research with policy frameworks, international cooperation, and community-based stewardship. Protecting marine megafauna is not only about conserving individual species but also about safeguarding the balance of ocean ecosystems where they act as apex predators and key ecological regulators, influencing food webs and habitat health across vast marine regions.