Abstract: This study estimated the prevalence of behavioral health conditions among military spouses and examined their associations with military life stressors. Participants were 17,485 spouses enrolled in Panel 2 (2020–2021) of the Millennium Cohort Family Study recruited from a representative sample of married service members with 1–5 years of military service across all branches and components. Population-weighted prevalence estimates were calculated for eight conditions: anxiety, depression, alcohol misuse, somatization, binge eating, insomnia, posttraumatic stress disorder (PTSD), and problematic anger. Logistic regression models examined associations between spouse-reported military life stressors and each condition. Results indicated that more than 40% of spouses reported at least one behavioral health condition, with somatization (24.4%; 95% CI 23.5–25.3) and anxiety (22.0%; 95% CI 21.1–22.8) being the most common. Nearly one-quarter reported multiple conditions. However, the majority of military spouses reported good overall behavioral health. Military life stress was positively associated with all eight outcomes. These findings suggest that addressing key sources of military life stress may help reduce the burden of behavioral health problems among military spouses.