Thermoelectric transducers have attracted significant attention owing to their immense potential in energy harvesting and biomimetic applications, such as waste heat recovery and the design of advanced thermal sensors. Although traditional thermoelectric semiconductors exhibit excellent thermoelectric performance at room temperature, their toxicity and rarity limit their practical applications. In recent years, with the emergence of advanced materials such as graphene, MXenes, and COFs, inspirations have been provided by biological thermosensitive ion channels to construct nanofluidic thermoelectric systems using these materials as fundamental building blocks, aiming to achieve efficient thermoelectric conversion. However, the thermoelectric coefficient of current nanofluidic membranes is only 1.27 mV/K in very dilute solution, much lower than that obtained by biological ion channels, that is, 5.8 mV/K. In this chapter, a detailed analysis of nanofluidic thermoelectric materials is conducted from the perspective of theoretical background, development, and applications. It is revealed that the synthetic effects of hydrodynamic slip and surface charge at the channel wall contribute significantly to the enhancement of thermoelectric properties. Furthermore, to design nanofluidic materials with better thermoelectric transducing performance, future strategies may involve integrating various external stimuli, such as pH control, electro-gating, or novel surface treatments, to advance their use in energy harvesting and biomimetic thermal sensors.