Developmental Dysplasia of the Hip (DDH) is the most common orthopaedic disorder in newborns. Whilst the Pavlik harness is one of the most frequently used treatments for DDH, there is immense variability in treatment parameters reported in the literature and in clinical practice, leading to difficulties in standardising teaching and comparing outcomes. In the absence of definitive quantitative evidence for the optimal Pavlik harness management strategy in DDH, we addressed this problem by scientifically obtaining international expert-based consensus on the same. An initial list of items relevant to Pavlik harness treatment was derived by systematic review of the literature according to PRISMA criteria and reviewed by two expert clinicians in DDH management. Delphi methodology was used to guide serial rounds of surveying and feedback to content matter experts from the International Hip Dysplasia Institute (IHDI), a collaborative group of paediatric orthopaedic surgeons with expertise in the management of DDH. Rounds of surveying continued in the same manner until consensus was reached. Importance ratings were derived from each round of surveying by calculating median score responses on the 5-point Likert scale for each item. Items requiring clarification or those with a median score of below 4 (“agree”) were modified as needed prior to each subsequent round. Consensus was considered reached when 90% or more of the items had an interquartile range (IQR) of ≤ 1. This value indicates low sample deviation and is accepted as having achieved consensus. This was followed by a corroboration of face validity to derive the final set of management principles. The literature search and expert review identified an initial list of 66 items in 8 categories relevant to Pavlik harness management. Four rounds of structured surveying were required to reach consensus. Following a final round of face validity, a definitive list of 33 items in 8 categories met consensus by the experts. These items were tabulated and presented as “General Principles of Pavlik Harness Treatment for DDH” and “Pavlik Harness Treatment by Severity of Hip Dysplasia”. Furthermore, highly contentious items were identified as important future areas of study and will be discussed. We have developed a comprehensive set of principles derived by expert consensus to assist clinicians, and for use as a teaching resource, in the non-operative management of DDH using the Pavlik harness. We have gained consensus on both the general principles of Pavlik harness treatment as well as the detailed treatment of hip subtypes seen across the spectrum of pathology of DDH. Furthermore, this study has also served to generate a list of the most controversial areas in the non-operative management of DDH which should be considered high priority for future study to further refine and optimise the outcomes of children with developmental hip dysplasia