Background: Identifying the interaction between dispositional and dynamic risk factors is necessary in understanding, predicting, and managing suicide risk. Interpersonal factors have consistently been linked to suicidal ideation over short-term periods. Additionally, distress tolerance may be a relevant dispositional protective factor against stressful events. Methods: Seven hundred and seventeen psychiatric inpatients (Male = 30.31%, Average Age = 40.71 years, Min = 14, Max = 82) self-reported their distress tolerance at hospital admission, and interpersonal needs and suicidal ideation on a daily basis. Dynamic structural equation modelling was used to examine whether within-level dynamics were moderated by distress tolerance. Results: Both perceived burdensomeness and thwarted belongingness were significantly associated with same-day suicidal ideation. Higher distress tolerance was associated with weaker daily associations between suicidal ideation and both perceived burdensomeness and thwarted belongingness. Distress tolerance was also associated with lower variability in suicidal ideation. Moderating effects were also evident when lifetime suicide attempts were added as a covariate, which was associated with stronger associations between interpersonal dysfunction and suicidal ideation, and higher variability in ideation. Conclusions: Distress tolerance may be important to consider when examining the dynamic relationships between suicidal ideation and proximal factors. Psychotherapy that specifically targets distress tolerance may be effective in reducing reactivity to interpersonal stressors.