This thesis will focus on the pervasive issue of child marriage, which continues to affectnumerous regions globally, presenting significant obstacles to the well-being and rights ofcountless children, especially that of young girls. To deepen the research, I have chosenNiger as a case study due to its alarming prevalence of child marriages. Estimated as oneof the world's poorest countries, Niger struggles with the prevalence of child marriages,which is a complex phenomenon linked with gender inequality. Despite ongoing efforts tocombat this issue, the occurrence of child marriages in Niger remains disturbingly high,with a profound impact on the agency, health, education, and socio-economic prospects ofyoung girls. The primary goal of my thesis is to analyze and explain how young girls'agency is affected. At the same time I will delve deeper into the factors that contribute tothe rise of child marriages and gender inequality in Niger and also the consequences of thispractice, specifically education and health. I will conduct a secondary data analysis,integrating secondary interviews in the discussion/analysis section. I will utilize both theFeminist Theory to explain gender inequality and the Capability Approach Theory toexplore how the agency of young girls is affected.