Saliva sampling is a non‐invasive method, and could be performed by donors themselves. However, there are few studies reporting biomarkers in saliva in the diagnosis of NPC. A total of 987 salivary samples were used in this study. First, EBV DNA methylation was profiled by capture sequencing in the discovery cohort (n = 36). Second, a q‐PCR based method was developed and five representative EBV DNA CpG sites (11 029 bp, 45 849 bp, 57 945 bp, 66 226 bp and 128 102 bp) were selected and quantified to obtain the methylated density in the validation cohort1 (n = 801). Third, a validation cohort2 (n = 108) was used to further verify the differences of EBV methylation in saliva. A significant increase of EBV methylation was found in NPC patients compared with controls. The methylated score of EBV genome obtained by capture sequencing could distinguish NPC from controls (sensitivity 90%, specificity 100%). Further, the methylated density of EBV DNA CpG sites revealed by q‐PCR showed a good diagnostic performance. The sensitivity and specificity of detecting a single CpG site (11 029 bp) could reach 75.4% and 99.7% in the validation cohort1, and 78.2% and 100% in the validation cohort2. Besides, the methylated density of the CpG site was found to decrease below the COV in NPC patients after therapy, and increase above the COV after recurrence. Our study provides an appealing alternative for the non‐invasive detection of NPC without clinical setting. It paves the way for conducting a home‐based large‐scale screening in the future. What's new? While various Epstein‐Barr virus (EBV)‐related biomarkers have been established as potential screening biomarkers for nasopharyngeal carcinoma, most of them rely on blood or nasopharyngeal swab samples. Using saliva samples, this study found a significant increase in EBV DNA methylation in nasopharyngeal carcinoma patients compared to controls. Detection at a single CpG site could reach a sensitivity of 75.8% and specificity of 99.7%. The methylated density of the CpG site was found to decrease below the cut‐off value after therapy and increase above the cut‐off value after recurrence. This study potentially provides a non‐invasive alternative for the detection of nasopharyngeal carcinoma.