IMPORTANCE Limited literature has characterized patterns of mental illnesses and barriers in seeking mental health care among police officers. OBJECTIVES To assess the prevalence of mental illness (diagnosis) and symptoms of mental illness, evaluate the characteristics of officers interested in seeking mental health care, and characterize perceptions of mental health care use. DESIGN, SETTING, AND PARTICIPANTS This survey study was conducted among officers at a large police department in Dallas-Fort Worth, Texas. Focus group sessions were conducted from April 1, 2019, to November 30, 2019, and the survey was conducted from January 1 to February 27, 2020. A total of 446 sworn, employed patrol officers who were present during the recruitment briefing were eligible to participate in surveys and focus groups. MAIN OUTCOMES AND MEASURES Officers reported lifetime or current diagnosis of depression, anxiety, and posttraumatic stress disorder, as well as current mental health symptoms (using validated screeners of depression, anxiety, posttraumatic stress disorder, and suicidal ideation or selfharm) and mental health care use in the past 12 months. Focus group data were collected to contextualize mental health care use. Logistic regression analyses were used for quantitative data, and focus groups were iteratively coded by 4 coders using inductive and deductive thematic identification. RESULTS Of the 446 officers invited to participate, 434 (97%) completed the survey (mean [SD] age, 37 [10] years; 354 [82%] male; 217 White [50%]). Of these officers, 19 (17%) had sought mental health care services in the past 12 months. A total of 54 officers (12%) reported a lifetime mental health diagnosis, and 114 (26%) had positive screening results for current mental illness symptoms. Among officers with positive screening results, the odds of interest in using mental health services was significantly higher for officers with suicidal ideation or self-harm than for those who did not (adjusted odds ratio, 7.66; 95% CI, 1.70-34.48). Five focus groups were conducted with 18 officers and found 4 primary barriers in accessing mental health services: (1) inability to identify when they are experiencing a mental illness, (2) concerns about confidentiality, (3) belief that psychologists cannot relate to their occupation, and (4) stigma that officers who seek mental health services are not fit for duty. CONCLUSIONS AND RELEVANCE The study found that although few officers were seeking treatment, they were interested in seeking help, particularly those with suicidal ideation or self-harm. Additional interventions appear to be needed to systematically identify and refer officers to health care services while mitigating their concerns, such as fear of confidentiality breach.