Organic thermoelectric (OTE) devices composed of pi-conjugated molecules are the basic building blocks for self-powered integrated organic electronics. In addition to molecular design and doping strategies, the highly tunable energy conversion process in OTE devices has drawn significant research interest. Specifically, the diverse physical properties of organic semiconductors, novel device geometry design, and advanced fabrication techniques combined enable the OTE device to be a powerful multiscale platform from single-molecular scale to thin films for modulating the TE performance, studying the fundamental charge transport mechanism, exploring novel energy conversion phenomenon, and realizing various functionalities. Here, the authors comprehensively review the recent experimental and theoretical advances in related topics of OTE devices, including multifunctional, external physical fields, and temperature modulated, as well as quantum OTE devices. The remaining issues and perspectives toward future OTE device research are also discussed at the end. Organic thermoelectricity (OTE) has garnered great attention. Recent OTE studies regarding device physics and applications are comprehensively reviewed, including field-modulated in-device charge transport phenomena, functional OTE devices such as stretchable and self-healing power generators, and single-molecular TE devices. Challenges and perspectives toward future novel OTE devices are also provided. image