Background: Correctional officers (COs) experience elevated rates of mental and physical ill-health as compared with other general industry and public safety occupations. The purpose of this study was to investigate demographic, mental health, job tenure, and work-family characteristics and their prospective association to burnout within and between jail officers during one year of new employment. Methods: In 2016, newly hired jail officers (N = 144) completed self-reported surveys across four time points in a one-year prospective study at a Midwestern United States urban jail. Linear mixed-effects and growth modeling examined how work-family conflict (W-FC) and depressive symptoms relate to perceptions of burnout over time. Results: Jail officer burnout increased and was related to rises in W-FC and depression symptoms. Within-person variance for W-FC (B_pooled = .52, p < .001) and depression symptoms (B_pooled = .06, p < .01) were significant predictors of burnout. Less time on the job remained a significant predictor of burnout across all analyses (B_pooled = .03, p < .001). Conclusions: Results from this study indicate that burnout increased during the first year of new employment; and increased W-FC, higher depression, and brief tenure were associated with burnout among jail COs. Future study of correctional workplace health is needed to identify tailored, multilevel interventions that address burnout and W-FC prevention and early intervention among COs.