Satellite remote sensing (RS) has emerged as a valuable tool for monitoring the water quality (WQ) and trophic status of optically diverse lakes, particularly in regions like Greece, characterized by varied aquatic ecosystems. Traditional in-situ methods for assessing WQ are often labor-intensive, costly, and limited in spatial coverage. RS provides a complementary approach, enabling frequent, wide-scale, and cost-effective monitoring. The optical diversity of lakes, influenced by factors such as varying chlorophyll-a (Chl-a) concentrations, suspended sediments, and dissolved organic matter, presents challenges in WQ assessment. RS techniques, leveraging spectral data from satellites, can effectively quantify WQ key indicators, which are crucial for determining trophic status. This chapter provides a comprehensive overview of specific RS applications across the National Lake Network Monitoring of Greece, conducted in accordance with the Water Framework Directive (WFD), focusing primarily on the empirical development of WQ quantitative models for Chl-a and total phosphorus concentrations, and Secchi Disk depths. Those same models’ performance was further validated from the perspective of different atmospheric correction (AC) methods, since accurate AC is crucial for applications especially where small differences in surface reflectance (SR) are significant. The proven capability of RS to provide consistent and timely data supports sustainable water resource management through the continuous monitoring of Greece’s optically diverse lake ecosystems.