In this article we show that the sporadic simple Harada group G is uniquely determined up to isomorphism by the centralizer CG(z) of a 2-central involution z of G. This strengthens Y. Segev's uniqueness theorem [24] which required the known structure of the centralizers of two non-conjugate involutions.Using the second author's algorithm [19], we also provide a self-contained existence proof for the Harada group G by giving matrix generators inside GL133(19).Furthermore, the character table of G is determined and representatives for the conjugacy classes of the group are given as short words in the generating matrices.