� “harm to the public and/or the public interest” is defined in article 1, point 2, and article 14 of law no. 5 of 1999. the interpretation of this term often raises legal issues because the competition authority is required to provide evidence of the impact analysis of the harm resulting from the prohibition on vertical integration, which requires further explanation. the main issue addressed in this thesis is determining harm to the public in vertical integration agreements based on article 14 of law no. 5 of 1999 and how the indonesian competition commission (kppu) applied the concept of harm to the public in its decisions no. 01/kppu-l/2003 and no. 13/kppu-i/2019. the research method used is normative law, supplemented by the use of secondary data; data collection was conducted through literature review, qualitative analysis, and the drawing of conclusions using deductive reasoning. the study concludes that the phrase “harm to the public” relates to consumer harm and public welfare through the theory of harm and plays a crucial role for the kppu regarding its authority to intervene or conduct investigations; the kppu’s supervisory role can be deemed nonexistent if the indonesian public suffers no harm whatsoever.