Suicide is one of the major causes of premature death in patients diagnosed with a schizophrenia-spectrum psychotic disorder. However, associations between psychotic-like experiences in youth and suicidality in later life remain under-researched. We aimed to investigate any associations between early experiences of thought interference and auditory-verbal hallucinations (AVHs) with first-rank symptoms of schizophrenia and suicidal thoughts and behaviours in adulthood. This study used data from the Avon Longitudinal Study of Parents and Children (ALSPAC). We calculated combined thought interference score at ages 11 years 8 months, 13 years 1 month, 14 years 1 month and 16 years 6 months. We also assessed AVHs at the same age points. For outcome variables, we used specific variables measuring delusions of control, AVHs and suicidality at 24 years of age. We carried out logistic regressions and mediation analyses to assess the relationships among these variables. Thought interference and AVHs at all ages throughout childhood and adolescence were associated with suicidal thoughts and behaviours, and also with clinically more significant symptoms of delusions of control and AVHs at age 24. Substance use-induced psychotic-like experiences mediated a large proportion of the relationship between early psychotic-like experiences and suicidality in later life. Thought interference and AVHs in childhood and adolescence are associated with first-rank symptoms and suicidality in adulthood. Mental health interventions in children and adolescents need to take into account the impact of specific psychotic-like experiences and allow for the early detection of thought interference and AVH-related symptoms.