This work presents a novel low complexity decoder for turbo product codes (TPCs). The new decoder, denoted as ultra-light decoder (ULD), can perform soft decision decoding without an algebraic hard decision decoder, which is the core of conventional soft decision decoders of block codes. Moreover, the unique structure of the ULD enables the design of a new approach to compute the minimum Euclidean distance (ED) at each decoding iteration. Therefore, the ULD offers significant complexity and delay reduction as compared to conventional TPC decoders. Reducing the complexity and delay will enable using codes with high code rates to improve the system spectral efficiency, or use powerful codes with low code rates to reduce the transmission power. The system bit error rate (BER) is presented for binary and M-ary modulation schemes over additive white Gaussian noise (AWGN) channels, and the coding gain is given for Rayleigh fading channels. The obtained numerical results show that the ULD offers coding gain that is comparable to conventional TPC decoders under various system and channel conditions, but with significantly lower complexity.