In this work, a single-event transient tolerant optical receiver using triple modular redundancy (TMR) is presented. The TMR method triplicates three identical receivers in parallel. Majority voting is performed at the outputs after the received signal has been sliced. The proposed SET tolerant optical receiver achieves a gain of 83 dB ohm, a bandwidth of 7.2 GHz, and an input-referred noise current of 0.93 micro Ampere rms. It operates at a supply voltage of 1 V and dissipates 33 mW of power. Analysis shows that adding TMR introduces a sensitivity penalty of only 0.8 dB.