A considerably higher rate of suicide exists among youth who are street-involved or homeless than among the general youth population. Research is needed to better understand the risk factors that predict suicidality within this vulnerable population. Our research makes a specific contribution in that it examines both suicidal ideation and attempts. Using data from a sample of 150 homeless and street-involved youth in Toronto, Canada we examine the relative impact of a range of background, street-related, drug use, and mental health variables. The results underscore the particular impact of depression and non-suicidal self-harm behaviour on suicidal ideation and attempts. The findings draw attention to the under-appreciated impact of experiences of bullying and on-street discrimination among this population. These two factors suggest a multi-dimensional process of rejection and social exclusion that begins in school and that continues on the street.