Applied Behaviour Analysis (ABA) uses our understanding of the science of behaviour to address issues of social significance (Baer, Wolf & Risley, 1968). One example is the support and education of children with autism, and there is a growing evidence base for the effectiveness of behavioural interventions with this population (Lai et al., 2014; Eldevik et al., 2012). However, getting evidence from research into practice is not straightforward (Rycroft-Malone, 2004). Translational or implementation science is the basis of this thesis. Two models from translational science (Rycroft-Malone, 2004; Fixsen et al., 2005), identify four factors critical to the successful implementation of evidence-based practice: core knowledge and skills; organisational processes which embed these into practice; consumer involvement in, and perceptions of the selection and evaluation of practices; and the wider national policy and regulatory framework. Using a range of research methods, this thesis explores these factors in relation to ABA as an intervention in the support and education of children with autism. Chapters include a description of the development of a competence framework for ABA (Chapter 2) and an example of a practical application of the framework – identifying ways of measuring staff competence (Chapter 3). Chapters 4 and 5 are both based upon and describe the first study in the UK to attempt to identify and quantify the use of behavioural interventions amongst a sample of UK parents and their beliefs about ABA; and Chapters 6 and 7 outline in two separate papers, the first study in the UK to explore the perceptions and experiences of commissioners of services in the support and education of children with autism. The findings from these studies are discussed in relation to theoretical models of implementation. The implications of these for the field of behaviour analysis are outlined and recommendations for further study are made.