Introduction The purpose of this study was to examine the association between prior emergency department (ED) visit or hospitalization and subsequent suicide attempt among homeless youth aged 10–17 years old. Methods With New York statewide databases, a case–control design was conducted. Cases and controls were homeless patients with an ED visit or hospitalization due to suicide attempt (cases) or appendicitis (controls) between April and December. We examined ED and inpatient records for 90 days prior to the visit for suicide attempt or appendicitis. The primary exposure variable was prior healthcare utilization for any reason other than the following four reasons: mental health disorder, substance use, self-harm, and other injuries. Multivariable logistic regression models, with year fixed effect and hospital random effect, were used. Results A total of 335 cases and 742 controls were identified. Cases had lower odds of prior healthcare utilization for any reason other than the four reasons listed above. (adjusted Odds Ratio [aOR]: 0.53, p-value = 0.03). Conclusions The association between prior healthcare utilization and decreased risk of suicide attempt among homeless youth may be due to comprehensive care provided during healthcare utilization. It may also reflect the presence of a social network that provided a protective effect.