Freshwater algae play a vital role in aquatic ecosystems due to their primary productivity and contribution to the food chain. Among them, phytoplankton are key biological indicators of water quality, reflecting ecological status and nutrient availability. The present study aimed to analyze the phytoplankton diversity in two freshwater lakes Ranikere and Dodderikere over a one-year period from May 2019 to April 2020. Water samples were collected monthly and phytoplankton were identified based on morphological characteristics such as thallus organization, cell shape, pigmentation and cellular arrangement. A total of 54 algal taxa were recorded across both sites. These included 6 species of Chlorophyceae, 5 species of Cyanophyceae, 22 species of Bacillariophyceae, 15 species of Zygnemophyceae, 5 species of Euglenophyceae and 1 species of Charophyceae. The class Bacillariophyceae showed the highest diversity, followed by Zygnemophyceae. The comparative analysis between the two lakes revealed that Ranikere Lake exhibited a higher abundance and diversity of phytoplankton than Dodderikere Lake, possibly is due to the differences in nutrient input, light penetration and ecological conditions. This study highlights the ecological significance of phytoplankton in freshwater systems and underscores their role as indicators of water quality. The findings can contribute to future ecological assessments and conservation strategies in freshwater habitats.