Abstract. We define Mellin amplitudes for the fermion-scalar four point function and the fermion four point function in three dimensions. The Mellin amplitude has multiple components each associated to a tensor structure. We examine the pole structure of the Mellin amplitude and show how each component factorizes on the dynamical poles. Compared to the scalar case, we have a novelty here in that each component has in general two series of poles corresponding to each primary exchanged. Finally, we discuss some explicit results for fermionic Mellin amplitudes for Witten diagrams and conformal Feynman integrals which nicely illustrate the general features.