Selective Laser Melting (SLM) is a revolutionary technology pertinent to many high-value applications in the biomedical, automotive, and aerospace industries. It has the potential to produce topographically optimized parts comprising of complex geometries previously not attainable by traditional subtractive manufacturing methods [1]. SLM components experience unique thermal histories specific to their build, significantly improving the subsequent quasi-static properties [4]. However, defects have been an unavoidable part of manufacturing in SLM components as lack of fusion (LOF) defects and gas pores originate during fabrication. These defects act as crack initiation sites and have largely been associated with short crack initiation and propagation [5]. This restricts their implementation to non-critical applications due to lower fatigue strength and a larger scatter in fatigue life as a result of high inherent porosity. To enable their implementation in safety critical applications, it is critical to develop an adept understanding of their process-microstructure-fatigue behaviour.