Software Product Line Engineering (PLE) exploits systematic reuse by identifying and methodically reusing software artifacts to develop different but related software systems. Developing Product Lines requires analysis skills to identify, model, and encode domain and product knowledge into artifacts that can be systematically reused across the development life-cycle. As such, Knowledge plays a paramount role in the success of the various activities of PLE. The objective of the KOPLE workshop series is to bring together SPL researchers and practitioners from academia and industry to investigate the role of Knowledge in PLE. Knowledge is usually encapsulated in PL architectures in a tacit or implicit way, and this may appear to be sufficient for industry to implement successful product lines. Nevertheless, KOPLE also aims to become a discussion forum about techniques and methods to convert from tacit to explicit Knowledge in PLE and to process and use this Knowledge for optimizing and innovating PLE processes.