HIV testing is a crucial strategy for HIV prevention, treatment, care, and support. However, its uptake is suboptimal among young people, particularly in settings where the HIV burden is highest. In Papua New Guinea (PNG), HIV testing and its predictors among young men are understudied. This study aimed to assess the prevalence and predictors of not testing for HIV among young men aged 15-24 years in PNG. Data were drawn from the 2016-2018 PNG Demographic and Health Survey (DHS). A total of 1,362 young men were included in the study. Multivariable logistic regression using the complex sampling technique was used to determine predictors of not testing for HIV. Results were reported as adjusted Odds Ratios (AOR) with 95% Confidence Intervals (CI). The prevalence of not testing for HIV among young men was 82.7%. Young men who were never married (AOR 1.88; 95% CI: 1.19-2.96), did not own a mobile phone (AOR 1.79; 95% CI: 1.17-2.77), had not paid anyone for sex (AOR 2.82; 95% CI: 1.29-6.14), and had no STIs (AOR 1.97; 95% CI: 1.00-3.85) had higher odds of not testing for HIV. The odds of not testing for HIV remained lower among young men who did not always use a condom during sex (AOR 0.62; 95% CI: 0.39-0.96). HIV testing among young men in this study was much lower, suggesting an urgent need to adopt novel prevention approaches to address this shortfall. Furthermore, youth-oriented health services should be prioritized with a focus on improving HIV knowledge, risk reduction, and behaviour change among young men in this setting.