The phytoremediation potential of seaweeds has gained significant attention in recent years due to their remarkable ability to clean up and restore polluted environments. They are useful tools in phytoremediation because of their distinct characteristics and diverse mechanisms. This chapter aims to explore the environmental cleanup abilities of seaweeds and shed light on their potential applications in phytoremediation. Seaweeds have the ability to remove a variety of contaminants, including nutrients, heavy metals, organic pollutants, and radioactive materials. Furthermore, they have demonstrated efficacy in the removal and detoxification of contaminants from aquatic ecosystems, coastal areas, and industrial sites. There are many benefits to using seaweeds in phytoremediation, including their vast availability, low cultivation costs, and capacity to restore ecosystem balance. However, challenges such as proper species selection, site-specific considerations, and long-term monitoring need to be addressed for successful implementation.