Energy dissipation in nanoelectronics has emerged as a critical bottleneck that limits both storage density and computational speed. Two-dimensional (2D) materials such as graphene and MoS₂, with their atomic-layer thickness and exceptional physical properties, offer promising solutions to these challenges. However, their ultrathin nature requires substrate support for mechanical stability, which in turn introduces strong interfacial effects that dominate overall heat transport. A significant portion of the dissipated energy transfers through the 2D material–substrate interface, making interfacial thermal resistance a key determinant of device thermal performance (Yue et al., Small. 7:3324–3333, 2011). This chapter focuses on Raman-based characterization techniques for investigating interfacial thermal transport. Section 5.1 introduces the fundamental principles of Raman thermometry as applied to interface studies. Section 5.2 presents the Raman penetration method. Section 5.3 describes the two-step Raman method for decoupling in-plane and cross-plane heat transport contributions. Section 5.4 discusses thermal resistance at nanoscale contacts, addressing localized phonon scattering and imperfect bonding effects. Section 5.5 explores strategies for modulating interfacial thermal resistance through interface engineering, surface functionalization, and heterostructure design.