The Third Sandia Fracture Challenge (SFC3) is a collaborative effort for assessment of the state-of-the-art predictive capability in ductile failure. The Challenge is designed such that computational modelers are asked to predict ductile failure in an unfamiliar geometry using provided standard materials data. The SFC3, issued in December 2016, is centered on an additively manufactured 316L stainless steel geometry with through holes and internal cavities that could not be produced by conventional machining. The provided information to enable the predictions includes: base material tensile behavior for different material configurations and loading rates; notched base material tensile behavior; fabrication drawings of the base material specimens and the Challenge (unfamiliar) geometry; electron backscatter diffraction of the Challenge geometry mid-plane; micro-computed tomography data of all Challenge geometry specimens; scanning electron microscope images of the fracture surface of tensile and notched tensile base material specimens; macroscopic images of fractured base material specimens; descriptions of the boundary conditions for the base-material and Challenge-geometry tests; questions to be answered for the prediction (quantities of interest); and an overview presentation of the Challenge.