This paper demonstrates how war may significantly enhance the authority of male youth to make claims on land, at the expense of the elders and customary authority. Conventional analyses of rural youth in Africa often describes their migration to cities in search of education and employment as due to land shortage which leaves elders and customary institutions firmly in charge. This paper, in contrast, suggests that in post-conflict environments an entirely different dynamic may take place, as the majority of youth remain in rural communities and become the new power holders over, or managers of, land. This argument builds on findings from ethnographic research conducted between 2011 and 2013 in Acholi sub-region in Northern Uganda. The analysis highlights different war-related processes through which youth claim and establish authority in land governance. First, after war, youth fill the vacuum in land governance left by the death of elders during the violence. Moreover, war favours youth in the ongoing struggle for authority; in particular when staying in IDP camps and participation in the war has eroded the conventional legitimacy of the elders. Third, youth are better disposed to seize opportunities created by war, notably the commodification of land. An important dynamic is also that war legitimizes violence as a way of claim making on land; a strategy which is mainly employed by youth. The paper concludes by asserting that this new (claims to) authority of youth in land governance may have irreversible effects on customary tenure, as ownership of rural land is becoming increasingly individualized.