The nationally funded Prevention and Early Intervention (PEI) programme aimed to design, deliver and evaluate interventions to improve a range of outcomes for children growing up in areas of low socio-economic status (SES). A key focus for many PEI programmes was to improve the oral language abilities of children, recognising its important link to a range of literacy, learning, social, emotional and behavioural indicators. This paper reviewed the published reports of PEI and community programmes that implemented oral language interventions for children, parents and practitioners. This mapping exercise demonstrated that the oral language interventions implemented varied extensively and were predominantly evaluated through gathering the perspectives of those receiving the supports. A noticeable gap was the lack of a national evaluation framework of the oral language interventions provided, resulting in difficulties making comparisons, determining impact and contributing to the evidence base of the effectiveness of bespoke interventions designed and delivered. Implications of this mapping exercise are outlined for the future implementation and evaluation of universal and targeted oral language interventions.