This study aimed to investigate suicide ideation and attempts in older women living alone and to identify the factors affecting suicide ideation. Methods: This is a cross-sectional correlational study using secondary data analysis. Original data (n=1,023) were collected using face-to-face interviews from August to October 2018 in Siheung city to investigate the need for health care and daily life support services. Study participants were 297 older women (age=74.67±5.35), with inclusion criteria being women≥65 years old and living alone, those without cognitive impairment(Mini-Mental State Examination-2 Standard Version (MMSE-2 SV)≥24), and those who could evaluate instrumental activities of daily living. Data were analyzed using descriptive analysis, independent t-test, Pearson's correlation coefficient, and multiple linear regression analysis. Results: Data analysis showed 26.9% of participants reported suicide ideation with a frequency of 4.14 out of 10 points. Among study participants, 8.8% had attempted suicide with an average of 2.65 attempts. Participants who had children thought about suicide more than those who did not. Living children, personal income, participation in economic activity, social support, depression, chronic diseases, frailty, and suicide attempts were significantly correlated with suicide ideation. Therefore, depression, frailty and suicide attempts were factors affecting suicide ideation for older women living alone. Conclusion: Our findings provide evidence that evaluating depression, frailty, and history of suicide attempts is important for suicide prevention in older women living alone.