Abstract. Let S be a compact surface of genus > 1, and g be a metric on S of constant curvature K ∈ {−1, 0, 1} with conical singularities of negative singular curvature. When K = 1 we add the condition that the lengths of the contractible geodesics are > 2π. We prove that there exists a convex polyhedral surface P in the Lorentzian space-form of curvature K and a group G of isometries of this space such that the induced metric on the quotient P/G is isometric to (S, g). Moreover, the pair (P, G) is unique (up to global isometries) among a particular class of convex polyhedra, namely Fuchsian polyhedra.This extends theorems of A.D. Alexandrov and Rivin-Hodgson [Ale42, RH93] concerning the sphere to the higher genus cases, and it is also the polyhedral version of a theorem of Labourie-Schlenker [LS00].Math. classification: 52B70(52A15,53C24,53C45)