A consistent criticism of the criminal justice system in Indonesia is that it is a dysfunctional judicial system plagued by systemic corruption and government interference. Consistency in sentencing decisions in terrorism offences is especially important given the high profile of these crimes and the severity of the punishment. Yet there have been very few evidence-based studies of sentencing in Indonesian courts and none in relation to terrorism offences. The aim of this study is to identify the factors that contribute to sentencing of terrorism offences in Indonesia through the interpretive lens of Southern criminology. This thesis examines 127 terrorism verdicts produced by Indonesian courts between 2002 and 2016. It undertakes a multi-dimensional approach of historical, legal and empirical analyses to provide an in-depth understanding of factors that affect sentencing decisions in terrorism cases. The historical analysis explains that prosecutions for terrorism today includes both radical Islamists, minority extremists and separatist groups willing to use violence against the state and society to achieve their goals. Legal analysis further explains how the existing sentencing regimes provide limited guidance for judges in determining punishment for terrorist offenders yet often result in a jail term of more than 10 years. The empirical findings show that the greater the harm to victims or property, the more severe the sentence length is likely to be. The qualitative analysis further explains that judges use their discretion to avoid the minimum mandatory sentence in specific circumstances, such as in the case of juvenile offender. A Southern criminology approach helps explain terrorism sentencing in the broader historical, legal, and socio-political contexts. The enduring impact of colonialism, authoritarianism, and the ‘war on terror’ discourse shape the way the laws are written and how judges determine the sentences of terrorism offences. These elements have to be understood as essential contextual factors to sentencing in terrorism trials in Indonesia and demonstrate the importance of a Southern criminology perspective.