Background: Hip arthroscopy for femoroacetabular impingement (FAI) in athletes, including military servicemembers, has resulted in variable outcomes. The prevalence of low back pain (LBP) and psychiatric disorders (PSYs) is high among patients undergoing hip arthroscopy. Purpose: To determine the effect of LBP, PSYs, and the combination of both on outcomes in servicemembers treated arthroscopically for FAI. Study Design: Cohort study; Level of evidence, 2. Methods: Between April 2016 and June 2020, a total of 108 consecutive active-duty servicemembers underwent hip arthroscopy by a single surgeon at a single military medical center. Servicemembers were grouped according to the presence of preoperative LBP (Group LBP), a PSY (Group PSY), or both (Group Both), and outcomes were compared with those of servicemembers without these comorbidities (Group None). The minimum follow-up was 6 months. The primary outcome measure was return to duty (RTD). Secondary outcomes included the Nonarthritic Hip Score (NAHS), Hip Outcome Score–Activities of Daily Living (HOS-ADL) subscale, and Hip Outcome Score–Sports (HOS-S) subscale. Results: All servicemembers’ final duty status was confirmed, with a mean follow-up of 2 years (range, 6 months–4.3 years). The prevalence of preoperative LBP and PSY was 27% and 39%, respectively. RTD was 59% (10/17) in Group LBP, 10% (3/30) in Group PSY, 0% (0/12) in Group Both, and 47% (23/49) in Group None. Compared with Group None, the risk of discontinuing military service was statistically higher in Group PSY (relative risk [RR], 1.70 [95% CI, 1.41-1.99]) and Group Both (RR, 1.88 [95% CI, 1.62-2.15]) but not in Group LBP (RR, 0.78 [95% CI, 0.15-1.40]). The mean preoperative secondary outcomes all significantly improved postoperatively in Group None (NAHS, 58 to 75 [ P < .001]; HOS-ADL, 63 to 74 [ P < .001]; HOS-S, 44 to 57 [ P < .001]). Among the comorbid groups, the mean HOS-S did not significantly improve (Group LBP, 45 to 48 [ P = .71]; Group PSY, 36 to 44 [ P = .22]; Group Both 43 to 45 [ P = .75]), and <50% of these servicemembers achieved HOS-S meaningful clinical benefit metrics. Conclusion: Preoperative LBP, PSY, and a combination of both negatively affected outcomes after hip arthroscopy. Preoperative counseling is crucial in setting realistic outcome expectations.