Post-general election reconciliation takes place to prevent polarisation and ongoing conflict after the general election in Indonesia. This research analyses and formulates post-2024 election reconciliation as a constitutional convention that must be implemented to maintain national unity and support progressive legal culture practices. The progressive legal culture refers to the character and culture of Indonesian society, emphasising the family dimension and noble values in society. This research is normative legal research, prioritising conceptual and statutory approaches. The research results confirm that constitutional conventions, as unwritten laws that must be obeyed, should fulfil several characteristics: repeated constitutional acts, substantially based on political ethics and constitutional morality, and having ethical binding force. When recognised as a constitutional convention, post-election reconciliation should serve as a moral and ethical framework that guides political actors and society in maintaining unity. The implication of post-election reconciliation as a constitutional convention is that it has ethical validity and must be implemented; however, if such reconciliation is not observed, it cannot be fair for the judicial institution. This research recommends the institutionalisation of post-election reconciliation as a constitutional convention, ensuring that Indonesia's legal culture prioritises morality and minimises societal divisions, safeguarding national unity and preventing social disintegration.