The thesis focuses on the internal dimension of the right to self-determination in public international law. The objective of the thesis is to explore the possibilities of deepening the normative foundations of the internal dimension of the right to self-determination in order to strengthen its claim as a viable alternative to external self-determination. The thesis does this through three different means: a) critically identifying the current status of the right to self-determination and its internal variant; b) offering a theory of internal self-determination and how it may relate to external self-determination; c) exploring how sub state actors have attempted to engage with their host states in a variety of contexts both in the Global North and South, and drawing from those experiences to restate/clarify how internal self-determination can play the role of a credible alternative to external self-determination. The thesis argues that the meaning of self-determination in this context can only be understood through examining the circumstances in which the law is being sought to be applied. The thesis identifies that the site of the circumstances in which internal self-determination is invoked is the constitutional law of states. The argument developed claims that through studying how constitutional law grapples with these issues we may normatively fine tune our understanding of internal self-determination. The thesis demonstrates how this may be done by engaging with a few case studies from the Global North and the South and provides tentative conclusions for bettering our normative understanding of internal self-determination.