This study aimed to assess the impact of photodynamic therapy (PDT) on the oral health-related quality of life (OHRQoL) among denture stomatitis patients with implant overdenture prostheses (IODs). The patients were recruited from a specialist dental practice according to selection criteria. The Candida spp. were identified and confirmed by the microbiological culture technique. Candida counts were estimated as colony-forming units (CFU/ml) at baseline, 15, 30, and 60 days. PDT was carried out twice a week with 72 h intervals for a period of 4 weeks. A structured questionnaire was used for data collection. It included the demographic details of the patients, including age, gender, education, marital and socioeconomic status (SES), oral habits, and smoking status. In addition, the Oral Health Impact Profile-EDENT (OHIP-EDENT) scale was added to assess the OHRQoL of all patients before and after PDT treatment. The data were analysed using descriptive statistics, the t-test and the Shapiro-Wilk test; statistical signifcance was set at p < 0.05. At baseline, the overall mean Candida CFU/ml were quite high in the implant overdenture (IODs) samples, 37.12 ± 15.8, as compared to palatal mucosa samples with 5.1 ± 2.3. After PDT treatment, a statistically significant reduction was noted in the mean Candida CFU/ml on both surfaces at all follow-up visits. It was observed that all domains of OHIP-EDENT except for physical disability and handicap showed statistically significant improvement in mean scores after PDT treatment. FL, P1, P2, D2, and D3 had statistically significant mean score improvements of 2.2, 3.1, 2.2, 1.4, and 0.7, respectively. Furthermore, after PDT treatment, the total OHIP-EDENT score showed a statistically significant improvement of 11.6. PDT treatment has a positive impact on the OHRQoL for patients with denture stomatitis. It can be used as an effective treatment option for the treatment of denture stomatitis in IOD patients.