Sleep routines that develop as an adaptation or reaction to deployment can persist upon return stateside. Sleep problems intensify and are intensified by psychiatric distress. This research presents the findings of a comprehensive survey of sleep impairment in relation to demographic data, military history, combat exposure, and mental illness symptoms among a general sample of 375 servicemembers and veterans of Operations Enduring Freedom and Iraqi Freedom (OEF/OIF) at a wide range of times postdeployment. Sleep impairment was assessed with the Pittsburgh Sleep Quality Index (PSQI) and the Addendum for PTSD. Posttraumatic stress disorder (PTSD), depression, and anxiety symptoms were evaluated, with the PTSD Checklist–Military, the Patient Health Questionnaire-9 and the Generalized Anxiety Disorder-7. Sleep problems were common across the sample, with 45.4% of participants reporting sleep onset greater than 30 minutes, 21.4% typically achieving less than 4.5 hours of total sleep time, and 56% reporting being awake in bed more than 15% of the night. Global PSQI scores classified 89% of the sample as “poor sleepers.” Sleep problems were more severe among servicemembers with less education, from lower ranks (E1-E3), with greater combat exposure, and greater depression, anxiety, and PTSD symptoms. These findings suggest the need for routine screening of sleep problems among veterans and increased professional training in interventions for insomnia and nightmares. For individuals experiencing sleep problems with concurrent psychiatric symptoms, addressing sleep concerns may be one less-stigmatizing way to transition servicemembers and veterans into needed mental health services.