Aquatic ecosystems, covering inland, coastal, and marine regions, are vast and vital components of the earth’s hydrosphere. These are necessary for life, ecosystem stability, and environmental conservation. People depend on aquatic ecosystems for drinking water, irrigation, recreation, storm protection, flood management, and aquifer restoration. Aquatic ecosystems face threats from urbanization, deforestation, illegal chemical and fertilizer discharges, pollution, unregulated activities, and extreme weather conditions due to climate change. Effective aquatic ecosystem management and conservation are needed to address these issues. Global aquatic ecosystem monitoring and conservation are complex due to its vastness and dynamic nature. Regular water monitoring could help in ecological rehabilitation and restore deteriorated ecosystems. Using satellite technology to monitor aquatic ecosystems can be a beneficial tool for everyone. Nowadays, real-time access to all geographical data is made possible by drones, satellites, airplanes, and other remote sensing devices, which makes analyzing spatial information quick and easier. Remote sensing at a global or regional level provides continuous monitoring at various spatial scales. In environmental research, remote sensing technology enables the efficient, economical, and sustainable measurement of various features and traits in several dimensions. Remote sensing strengthens the precision of measuring parameters such as sea surface temperature, salinity, color, winds, eutrophication level, and other water quality parameters. Additionally, it can evaluate the impacts of pollution and climate change on aquatic ecosystems and safeguard them. This chapter covers current satellite platforms and sensors, the accessibility of datasets, and the image-processing technology used for monitoring aquatic ecosystems.