In this paper, we study approximate Hadamard matrices, that is, well-conditioned $n\times n$ matrices with all entries in $\{\pm1\}$. We show that the smallest-possible condition number goes to $1$ as $n\to\infty$, and we identify some explicit infinite families of approximate Hadamard matrices. Bibliographic Tools Code, Data, Media Demos Related Papers About arXivLabs arXivLabs is a ...