The workshop will showcase recent research in the field of Computational Biology. There has been significant development in genomic sequencing techniques and imaging technologies. These approaches not only generate huge amounts of data but provide unprecedented resolution of single cells and even subcellular structures. The availability of high dimensional data, at multiple spatial and temporal resolutions has made machine learning and deep learning methods increasingly critical for computational analysis and interpretation of the data. Conversely, biological data has also exposed unique challenges and problems that call for the development of new machine learning methods. This workshop aims to bring together researchers working at the intersection of Machine Learning and Biology to present recent advances and open questions in Computational Biology to the ML community. The workshop is a sequel to the WCB workshops we organized in the last three years Joint ICML and IJCAI 2018, Stockholm, ICML 2017, Sydney and ICML 2016, New York as well as Workshop on Bioinformatics and AI at IJCAI 2015 Buenos Aires, IJCAI 2016 New York, IJCAI 2017 Melbourne which had excellent line-ups of talks and were well-received by the community. Every year, we received 60+ submissions. After multiple rounds of rigorous reviewing around 50 submissions were selected from which the best set of papers were chosen for Contributed talks and Spotlights and the rest were invited as Posters. We have a steadfast and growing base of reviewers making up the Program Committee. For the past edition, a special issue of Journal of Computational Biology will be released in the following weeks with extended versions of 14 accepted papers. We have two confirmed invited speakers and we will invite at least one more leading researcher in the field. Similar to previous years, we plan to request partial funding from Microsoft Research, Google, Python, Swiss Institute of Bioinformatics that we intend to use for student travel awards. In past years, we have also been able to provide awards for best poster/paper and partially contribute to travel expenses for at least 8 students per year. The Workshop proceedings will be available through CEUR proceedings. We would also have an extended version to be included in a special issue of the Journal of Computational Biology (JCB) for which we already have an agreement with JCB.