This article examines how people's confidence in their governments changed in the context of South Korean decentralisation. South Korea provides a unique case to answer the question because it is one of the world's most rapid modernisers and has maintained autonomous local systems across three decades of decentralisation. Analysing data from the first and fourth wave of the Asian Barometer Survey in a seemingly unrelated regression (SUR) model, we find that the trust function of the local governments correlates with the trust function of the national government in 2003 and then disappears in 2015. We understand this finding as a piece of indirect evidence that South Korean local autonomy encourages local government trust, which does not reflect merely trust in the national government. This article also discusses the need for normalisation of the National Assembly, the creation of regional political parties and the dispersion of presidential power.