Springs are important freshwater supplies for communities, however, the spring water quality is increasingly threatened by growing anthropogenic pressures. Many springs in the Merapi spring belt are primarily allocated as recreation spots, although a number of them remain utilized by local communities for freshwater fisheries, irrigation, and even drinking purposes. This study assessed the physicochemical characteristics (pH, TDS, EC, nitrate, DO, COD, and Fe) and microplastic contamination of seven volcanic springs in Klaten Regency, Indonesia. Microplastics were identified using the NOAA microscopic method and quantified through abundance and Pollution Load Index (PLI), while water quality data were analyzed using descriptive statistics and hierarchical cluster analysis. Most parameters complied with WHO guidelines and Indonesia’s Water Quality Standards (Government Regulation No. 22 of 2021, Class I). However, elevated pH and nitrate concentrations in several springs (e.g., Jolotundo, Pelem, and Duda) indicate anthropogenic influence. Cluster analysis grouped these springs into three categories, where Tirto Mulyono and Brondong had the closest similarities in water quality due to natural conditions and human activities. Microplastics were present in all samples (n = 217 particles) with a mean abundance of 332.42 particles/L, predominantly fibers (71.89%), films, and fragments occurring in smaller proportions. Particle sizes ranged from 0.1 to 3 mm and 0.05 to 3 mm, respectively. Principal component analysis suggests that contamination is linked to localized human activities such as recreation and domestic use. CF values (1–3) and PLI (>1) indicate moderate contamination. These findings highlight the vulnerability of volcanic spring systems to microplastic and nutrient pollution, emphasizing the need for improved management, source separation, and infrastructure development.