This study was conducted to analyze water quality in a coastal province of Vietnam using multivariate statistical methods, namely cluster analysis (CA) and principal component analysis (PCA). Twelve parameters including pH, dissolved oxygen (DO), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrite (N-NO2−), nitrate (N-NO3−), ammonium (N-NH4+), orthophosphate (P-PO43−), chloride (Cl−), iron (Fe), and coliforms were collected at 10 locations in the dry season in 2020. The results showed that surface water was polluted by TSS, organic matters, nutrients, salinity, and coliforms compared to the national technical regulation on surface water quality (QCVN 08-MT: 2015/BTNMT). Cluster analysis results classified the original 10 sampling locations into 3 groups due to BOD, COD, TSS, N-NH4+, N-NO2−, coliforms, and salinity. Principal component analysis (PCA) revealed that 3 principal components (PCs) can explain 84.5% of the variance of surface water quality parameters in the study area. Moreover, pH, TSS, DO, BOD, COD, N-NH4+, N-NO2−, N-NO3-, P-PO43−, coliforms, and Cl‑ were the key variables that influenced surface water quality in the dry season. The findings in this study can provide useful information for policymakers in developing the program of surface water quality management and protection.