Background: The rate of high-risk drinking, a major cause of type 2 diabetes mellitus (T2DM), is increasing among Korean men. This study descriptive survey whether quality of life (QoL) mediates the relationship between drinking and 10-year T2DM risk scores in adult Korean men. Methods: We further analyzed data from the 7th Korea National Health and Nutrition Examination Survey 7th (KNHANES VII) from 2016 to 2018, selecting 4134 men aged 40–69 years who were not diagnosed with T2DM. The data were analyzed using complex sample regression; after analyzing the mediation. Results: In step 1 of the regression, the drinking rate significantly predicted QoL (\beta = 0.08, p 0.001), and in step 2, the drinking rate significantly predicted the 10-year T2DM risk score (\beta = 0.08, p 0.001). In step 3, the drinking rate (\beta = 0.08, p 0.001) and QoL (\beta = –0.09, p 0.001) were found to significantly predict the 10-year T2DM risk score, confirming that QoL partially mediates the 10-year T2DM risk score (z = –3.62, p 0.001). QoL was found to mediate the relationship between the drinking rate and 10-year T2DM risk score. Conclusions: Sex-specific risk factors must be considered to reduce the incidence of T2DM, and measures to promote healthy drinking habits need to be implemented to reduce the incidence of T2DM in men. Furthermore, these findings highlight the need to develop and actively implement various practical intervention strategies to enhance QoL.