A tsunami is a large wave caused by a disturbance in the sea, such as an earthquake, volcanic eruption, or underwater landslide. This phenomenon can cause serious damage to both human life and the environment. Tsunamis not only destroy buildings and infrastructure, but also damage marine and land ecosystems. One of the direct impacts of tsunamis on the environment is the destruction of natural habitats. For example, coastal areas rich in mangroves, coral reefs and seagrass beds are very vulnerable to these large waves. Loss of coastal vegetation exacerbates soil erosion, which in turn causes additional damage to aquatic habitats. Coral reefs, which are home to many species of fish, can also be destroyed by the force of waves, resulting in reduced marine biodiversity. The cumulative impact caused by tsunamis also changes the salinity of fresh and sea water. Polluting freshwater sources with saltwater can disrupt agriculture and threaten local food security. If agricultural land is contaminated, these impacts can persist for years, resulting in significant economic losses. Water quality is also affected because tsunamis transport waste and hazardous materials into the sea. Chemicals originating from factories, oil and submerged household waste can damage aquatic ecosystems. Plankton, which is the main food for many fish species, can also be contaminated, causing a chain impact on the marine food chain. In addition, tsunamis can cause wider pollution by circulating microplastics and waste into the marine environment. Microplastics have the potential to enter seafood and threaten human health. Research has shown that marine organisms exposed to microplastics can experience metabolic and developmental disorders. Tsunamis can also affect local communities that depend on natural resources to live. Damage to fishing areas can reduce fishermen’s income and increase economic instability. As a result, many communities may have to seek unsustainable alternatives, such as deforestation for agriculture, which could worsen environmental impacts. Poor management of post-tsunami recovery can also worsen the ecological situation. Unplanned development activities can reduce the ecological function of the area and increase the risk of disasters in the future. Therefore, it is important to involve environmental experts and local communities in post-tsunami recovery planning to achieve a more sustainable approach. Awareness of the impact of tsunamis on the environment is increasing. Many countries and organizations are now developing better mitigation and recovery strategies to deal with this threat. Sustainable management is critical to minimizing environmental impacts, accelerating ecosystem recovery, and protecting vulnerable communities from similar disasters in the future.