Abstract: Objective The purpose of this study was to examine the relationships between low back pain (LBP) and trunk endurance (TE) in a United States Veteran population. Methods Data were collected from the Veterans Affairs Palo Alto Healthcare System electronic health records (01/2019-12/2019) to identify adults aged 18-89 years presenting with nonsurgical LBP for a chiropractic consultation. Coefficient estimates, standard error, and P-values were calculated from multivariable linear regression for primary (LBP severity) and secondary (functional disability) outcomes, controlling for age, sex, and body composition. Results A total of 85 patients (mean age 53.6 years) were included. Trunk endurance was significantly associated with LBP severity (β: −0.042, P < .001) and Oswestry disability index (ODI) scores (β: −0.334, P < .001) suggesting that participants with greater TE (ie, longer prone bridge (plank) test time) had lower LBP severity and lower functional disability than those with poorer TE. Conclusion In this sample of Veterans, higher LBP severity and greater functional disability (ODI scores) were associated with reduced TE. Body mass index did not significantly influence these relationships.