It is undeniable that microplastics are found in many types of water, including drinking water. This study aims to investigate the presence of microplastics in one of the drinking water sources widely used by communities in Indonesia, namely unbranded refilled drinking water. The investigation was conducted at eight unbranded refilled drinking water depots in Karawang, West Java. A total of 2.00 L of raw and treated water samples were collected from each depot, prepared following the National Oceanic and Atmospheric Administration method, analyzed using an Olympus BX-41 microscope at tenfold magnification, and manually counted. The results showed that both raw and treated water from all unbranded refilled drinking water depots contained microplastics, with concentrations ranging from 15.50–42.00 particles/L and 6.50–17.50 particles/L, respectively. The dominant microplastics identified were fibers and fragments, with sizes ranging from 1.00–3.00 mm and less than 1.00 mm. Furthermore, the dominant color of the microplastics was black, indicating that the polymers were likely polyethylene, polypropylene, or polystyrene. This study provides novel evidence on microplastic contamination in unbranded refilled drinking water in Indonesia, offering baseline data for future environmental monitoring and risk assessment. These findings confirm that refilled drinking water consumed by communities in Indonesia may represent a potential pathway for the entry and accumulation of microplastics in the human body, posing significant health risks. Based on current findings, further research is required to improve water treatment performance and enhance public health protection.