Background Chlamydia and gonorrhea have increased nationally and in the US Army. Rates reported in the Army are elevated relative to the general population, partly because of differing population demographics. Methods Age- and sex-specific chlamydia and gonorrhea case rates among Army active component soldiers and the wider 18- to 64-year-old US adult population were computed from reports submitted through national and military surveillance systems in 2015 to 2019. Rates were standardized using the 2015 Army age and sex population distribution. Multivariable generalized linear models were generated to evaluate associated risk factors. Results Army age- and sex-adjusted chlamydia rates (per 100,000 person-years) were nearly twice those of US adults (2019 rates, 2317 vs. 1241), whereas US age- and sex-adjusted gonorrhea rates surpassed Army rates (2019 rates, 536 vs. 396). Chlamydia and gonorrhea rates were significantly elevated in Army women younger than 25 years relative to US women aged 18 to 24 years (2015-2019 crude rates, 10,404 Army/4243 US for chlamydia and 1014 Army/694 US for gonorrhea). Gonorrhea rates were significantly elevated in US men aged 25 to 44 years (2015-2019 crude rates, 506 US/251 Army and 223 US/86 Army for men aged 25-34 and 35-44 years, respectively). Age, sex, and race-ethnicity were significantly associated with infection among soldiers. Conclusions Observed increases in chlamydia and gonorrhea and identified risk factors are consistent with those reported nationally. Higher adjusted chlamydia rates among soldiers may reflect greater individual or sexual network risks, screening biases, or increased health care access. The Army's lower adjusted gonorrhea rates may reflect differences in high-risk subgroups (e.g., men who have sex with men), differing sexual networks, or other confounders.