Summary: We introduce a fractional version of the illumination problem of Gohberg, Markus, Boltyanski and Hadwiger, according to which every convex body in \(\mathbb R^d\) is illuminated by at most \(2^d\) directions. We say that a weighted set of points on \(\mathbb S^{d-1}\) illuminates a convex body \(K\) if for each boundary point of \(K\), the total weight of those directions that illuminate \(K\) at that point is at least one. We prove that the fractional illumination number of any o-symmetric convex body is at most \(2^d\), and of a general convex body \(\binom{2d}{d}\). As a corollary, we obtain that for any o-symmetric convex polytope with \(k\) vertices, there is a direction that illuminates at least \(\lceil\frac{k}{2^d}\rceil\) vertices.