Resumen: Background: Suicidal ideation (SI) is prevalent and associated with negative mental health outcomes in young people, including psychiatric symptoms and non-suicidal self-injury (NSSI). These associations are not well understood, as is the role of experiential avoidance (EA) in the maintenance of SI in university students. Method: The association between recent (last 30-days) and future (next 12-months) SI with NSSI, depression, anxiety, perceived life stress, and EA was explored in university students who completed an online survey (N = 1,355; 69 % women). Logistic regression analyses were used to predict recent and future SI. Interaction effects were explored to assess the moderating role of EA between NSSI, psychiatric symptoms, and SI. Results: Past-NSSI plus past-SI were strongly associated with recent SI (OR = 6.08) and future SI (OR = 25.36), even over and above current psychiatric symptoms. Additionally, EA moderated the relationship between psychiatric symptoms and recent SI. Specifically, anxiety and perceived life stress were associated with an increased risk of recent SI in students with low EA, compared to those with high EA. Limitations: The cross-sectional design does not allow us to infer causal relationships between variables. We only evaluated past NSSI and past SI with a single dichotomous item. Then, we did not capture the full heterogeneity of methods related to both phenomena. Only first-year university students were included and a convenience sampling method was used. Conclusions: Past-NSSI and past-SI are risk factors in the maintenance of recent and future SI, whereas EA operates as a specific moderating mechanism for SI.