Understanding and applying the Aboriginal and Torres Strait Islander Child Placement Principle (ATSICPP) is the first in a new series of resources being produced by SNAICC to support better implementation of the ATSICPP. The paper provides a definition of the five core elements of the ATSICPP and guidance on a best-practice approach to implementing its full intent. It is designed primarily for professionals engaged in legislation, policy and program design. The resource has been informed by the work of the Aboriginal and Torres Strait Islander Working Group for the National Framework for Protecting Australia’s Children 2009-2020.