This thesis explores how ontological security shapes Ukrainian memory politics in the Russia-Ukraine conflict and the Russian invasion's effect on ontological security. Despite their interdependence, ontological security and memory politics are seldomly studied together. Ukrainian memory politics, particularly in the post-Soviet era and after the implementation of the 2015 decommunization laws, have attracted European scholarly attention, as the Russo-Ukrainian (Memory) war has impacted Self and Identity on multiple levels. Furthermore, the thesis highlights the role of memory political measures in creating securitized unitary narratives, emphasizing the significance of memory for stability of Self. While unpopular at first, the decommunization laws emerged from the conflict and enhanced ontological security by solidifying a common Identity.