The spherical Deligne complex is a simplicial complex introduced in Deligne's work when he studied the K(pi,1) problem for some complex hyperplane arrangement complements. The complex is homotopic to a wedge of spheres, and bear some similarities with spherical buildings, though it is not a building. While the topology of this complex prevent a CAT(0) metric on it, we show that it contains large pieces supporting equivariant non-positive curvature metric. As an application, we deduce new results on the K(pi,1) conjecture for several classes of Artin groups.