Models where the Higgs field is a composite pseudo Nambu-Goldstone Boson (NGB) and the other Standard Model (SM) fields are partially composite (partial compositeness) represent one of the most interesting scenarios of new physics beyond the SM. We construct UV completions of such models, when the composite sector admits a weakly coupled description. The strongly coupled sector is identified as the low energy description of an $SO (N)$ supersymmetric gauge theory with matter fields in the fundamental of the group. The Higgs is a NGB associated to an $SO(5)/ SO(4)$ coset of a global symmetry group and is identified with certain components of matter fields in a Seiberg dual description of the theory. The SM gauge fields are obtained by gauging a subgroup of the global group. The mass mixing between elementary SM and composite fermion fields advocated in partial compositeness arise from the flow in the IR of certain trilinear Yukawa couplings defined in the UV theory. Most qualitative properties of the bottom-up constructions are derived. The masses of gauge and fermion resonances in the composite sector are governed by different couplings and can naturally be separated. Accommodating all SM fermion masses within the part.