Upconversion photoluminescence, an anti-Stokes process in which the emitted photon energy exceeds the excitation photon energy, can effectively achieve energy renormalization and conversion, with great application prospects in fields such as biological imaging, solar cells, photocatalysis, and optical refrigeration. As a strategically important new material in the post-Moore era, two-dimensional materials are crucial in realizing efficient room-temperature excitonic upconversion because of their large dipole moments, narrow linewidths, low disorder, and high exciton binding energies, which have recently attracted extensive research interest. This study first introduces the luminescence mechanisms used to achieve photon upconversion, including phonon-assisted upconversion, two-photon absorption, and Auger recombination. Then, research on upconversion based on two-dimensional material systems, such as hexagonal boron nitride, monolayer transition metal dichalcogenides, and two-dimensional perovskites, is summarized. Modulation and enhancement approaches for upconversion in two-dimensional materials that target low upconversion efficiency are also discussed. Finally, application prospects of excitonic upconversion effects in two-dimensional material systems are envisioned.