A true random bit generator (T-RBG) based on optoelectronic oscillator (OEO) with randomly distributed feedback is proposed and experimentally demonstrated. Through the implementation of a random fiber Bragg grating (RFBG) inside the OEO loop, a randomly distributed feedback is introduced into the proposed scheme, which allows it to produce broadband random signal and be used as entropy source. The random sequence can be obtained at a rate of 250 Gbps (50 GS/s × 5 bits) in real time, and it successfully passed all the NIST SP 800-22 tests.