Abstract: This study from a national sample of Gulf War Veterans (N = 1098) examined the association between physical activity level and (a) past-year suicidal ideation and (b) risk for suicidal behavior as defined by a score of > 7 on the Suicidal Behaviors Questionnaire-Revised. Forty-eight percent of the sample self-reported an active activity level based on items from the Rapid Assessment of Physical Activity. Twenty-four percent of underactive veterans reported suicidal ideation in the past year compared to 12% of active veterans. Results of logistic regression models indicated that physical activity level was uniquely related to suicidal ideation (OR = 0.63, 95% CI 0.43-0.91) and high risk of suicidal behavior (OR = 0.66, 95% CI 0.44-1.00) after accounting for key covariates known to be associated with suicide risk including pain, self-rated health, depression, posttraumatic stress disorder, alcohol and substance use disorder, nonsuicidal self-injury, and current psychosocial functioning.