This study was conducted to identify factors influencing the development of suicidal ideation and the transition from suicidal ideation to attempts by focusing on experiences of age discrimination and neglect among older Korean adults. This study analyzed data from 10,042 older adults from the 2017 National Survey of Older Koreans using national representative samples. Multiple logistic analyses were used to identify factors influencing the development of suicidal ideation and transition from suicidal ideation to attempts. While younger age, higher educational attainment, living alone, number of chronic diseases, depressive symptoms, social isolation, social support, experience of neglect, and age discrimination influenced the development of suicidal ideation, all of these did not influence the transition from ideation to attempts. Factors influencing this transition included male gender, less educational attainment, and experience of age discrimination. Thus, social efforts to reduce age discrimination are necessary to prevent suicide attempts among Korean older adults.