The Polymer Composites and High Performance Materials Workshop will be offered as a 4-day workshop and professional networking session July 21 - 24, 2019 in Rohnert Park (Sonoma County), California USA. This 4th in a series workshop will again bring together researchers from industrial, academic and government laboratories to discuss the state-of-the-art in polymer matrix composite science for aerospace, marine and infrastructure applications. The purpose of this workshop is to address key challenges and advances in the area of polymer composites, with specific emphasis on addressing fundamental structure-processing-property issues. The workshop will be Gordon Conference style, with discussion sessions and panels, to allow extensive interactions among participants.