Objectives: This study explored genetic and drug-induced hearing loss by focusing on the m.827A>G variation of the MT-RNR1 gene. In particular, we investigated the variant’s frequency, its association with hearing loss, and its potential interaction with gentamicin-induced damage within the Taiwanese adult population. Design: The study included 59,091 participants from the Taiwan Precision Medicine Initiative dataset. We examined the relationship between m.827A>G variant carriers, age, gentamicin exposure, and sensorineural hearing loss. Pure-tone audiometry assessed hearing thresholds and severity, while genetic analysis determined the mutation frequency. Phenome-wide association studies established connections between the variant and clinical diagnoses. Results: Genotyped from 58,091 Taiwanese adults, the m.827A>G variant minor allele frequency was 4.49%. Analyzing data from 186 carriers included age, sex, and audiograms. The carriers of m.827A>G variant who had been exposed to gentamicin did not display significant hearing level distinction. PheWAS analysis was conducted and confirmed a significant association between the variant and hearing loss. Conclusions: This study confirms the association between the m.827A>G variant and hearing loss, while suggesting that its role in gentamicin-induced ototoxicity may be limited.