 Thermoelectric materials have been widely studied due to their potential to generate electricity from waste heat. Two-dimensional, 2D materials such as graphene, black phosphorus, transition metal dichalcogenides, IVA via compounds, and emzines have shown promising thermoelectric properties and have received much attention in recent years. These materials possess unique physical and chemical properties which make them ideal candidates for thermoelectric applications. This paper reviews the progress made in developing 2D materials for thermoelectric applications, including theoretical simulations and experimental preparations. Additionally, nanoscale device structures and novel applications of 2D thermoelectric materials are discussed. Finally, current challenges and future opportunities are outlined. This article was authored by Dalongli, Yuning Gong, Yuesheng Chen, and others.