A probabilistic bit (p-bit) is the fundamental building block in the circuits of probabilistic computing, which produces a continuous random bitstream with adjustable probability. Here, we demonstrate a p-bit design utilizing the thermal noise-induced randomness in ferroelectric FET (FeFET). The domain dynamic in the FE material is found to play a crucial role in FE p-bits’ stochasticity, as the domain coupling suppresses the dipole fluctuation. The FE p-bits possess the advantages of both extremely low hardware cost and scalability with CMOS technology, rendering it a promising candidate for probabilistic computing circuitry.