Quantum-dot cellular automata (QCA) are a promising nanotechnology to implement digital circuits at the nanoscale. Devices based on QCA have the advantages of faster speed, lower power consumption, and greatly reduced sizes. In this paper, we are presented the circuits, which generate random numbers in QCA. Random numbers have many uses in science, art, statistics, cryptography, gaming, gambling, and other felds. Te base of these circuits is the linear feedback shif register (LFSR). In this paper, an optimized QCA LFSR is designed, and then different random number generators (RNGs) using XOR and adder are presented. Tese circuits generate different random numbers in each simulation. Te results show that our QCA designs are really fast and optimized in comparison with the previous CMOS and QCA designs.