This cross-sectional design study was undertaken to determine the factors associated with suicidal ideation in human immunodeficiency virus (HIV)-infected older adults. Data from a city-wide representative sample collected by the Seoul Metropolitan Government were used. The cross-sectional survey was conducted between February and March 2013. Participants selected and included in the analysis were HIV-infected adults living in Seoul, and aged 50 years and older. The overall adjusted model showed that being unemployed (adjusted odds ratio [aOR], 3.34; 95% confidence interval [CI], 1.16-9.57), a history of depression treatment (aOR, 4.61; 95% CI, 1.02-20.66), perceived belongingness (aOR, 0.63; 95% CI, 0.41-0.99), and psychological functioning (aOR, 0.85; 95% CI, 0.73-0.99) were significantly related to suicidal ideation. Psychosocial features were found to be strongly associated with suicidal ideation among HIV-infected older adults. The findings could be useful for HIV nursing consultants to identify HIV-infected older adults who are vulnerable to suicidal ideation. Comprehensive mental health services should be provided as coping resources for HIV-infected older adults who have suicidal ideation.