In recent years, nitrogen dioxide (NO2) is an emergent atmospheric pollutant that is detrimental to both human health and the environment. To overcome this, there is an increase in the utilization of gas sensors for day-to-day life and industrial purposes. In the quest of suitable candidates for NO2 gas sensing, metal oxide and two-dimensional (2D) material specifically MXene have gained attention due to the advancement of metal conductivity and distinctive structures. However numerous studies displayed that neither individual MXene nor pure metal oxide can exhibit excellent sensor response. This chapter aims to provide a comprehensive review of MXene-metal oxide based heterostructure as a NO2 gas sensor. And including a comparison of the NO2 detection efficacy based on hybrid MXene-metal oxide and composite as well. Additionally, the main difficulties in using MXene and its associated materials have been addressed. Also, future developments in related fields could lead to the development of high-performance ambient temperature NO2 gas sensors.