Angiogenesis – the growth of new blood vessels from the existing vasculature – is required to initiate tissue vascularization and wound healing. Improperly vascularized grafts, constructs, and wounds fail to integrate with the host, resulting in tissue necrosis. Extracellular matrix (ECM) structure has been identified as a potential therapeutic target due to the numerous mechanisms by which the ECM influences angiogenesis. However, it is unclear how interactions between differing structural features of the ECM affect microvascular growth and angiogenic signaling. The overall aim of this research is to investigate how spatial configurations of ECM structural features – namely, collagen density and the degree of collagen fibril alignment (i.e., anisotropy) – affect neovascular guidance and growth during angiogenesis using a combination of experimental and computational approaches. In Aim 1, we investigated the role of collagen density and fibril orientation on neovessel growth and at an in vitro tissue interface. Microvessels were deflected by elevated matrix density and fibril alignment was involved in guiding deflected microvessels along the interface. Further, spatial patterning of VEGF-secreting tissue-resident macrophages enabled microvessels to overcome structural barriers and cross tissue compartments. In Aim 2 we explored the isolated and combined effects of matrix density and anisotropy on microvessel guidance. An in vitro system to align collagen hydrogels to increasing degrees of anisotropy and density was developed and used to study microvessel cultures. Matrix alignment was found to increase microvessel growth and guidance, although these effects were attenuated by increased matrix density. Finally, in Aim 3, we updated AngioFE, a plugin for FEBio (Finite Elements for Biomechanics) to enable the simultaneous use of matrix anisotropy and density as guidance cues in simulations of angiogenesis. This was accomplished by representing the local collagen orientation as ellipsoidal fibril distributions which inherently encode the direction and degree of alignment. Predictive simulations accounted for changes in growth and guidance in response to differing configurations of matrix density and alignment in anisotropy gradients and clinically-relevant matrix structures found at tumor peripheries in certain cancers. The results of this dissertation extend our current understanding of how cell-matrix interactions during angiogenesis affect vascularization outcomes.