The ISWC 2015 Poster and Demonstration track complements the Research Paper track of the conference and o ers an opportunity for presenting late-breaking research results, ongoing research projects, and speculative or innovative work in progress. The informal setting of the track encourages presenters and participants to engage in discussions about the presented work. Such discussions can be a valuable input into the future work of the presenters, while o ering participants an e ective way to broaden their knowledge of the emerging research trends and to network with other researchers. These proceedings contain the extended abstracts of all accepted posters and demos presented at Posters and Demos Track of ISWC 2015. Posters range from technical contributions, reports on Semantic Web software systems, descriptions of completed work, and also work in progress. Demonstrations showcase innovative Semantic Web related implementations and technologies. This year we had 126 submissions, of which the program committee accept 44 posters and 55 demos. We would like to take this opportunity to thank all of the authors for their contributions to the ISWC 2015 programme! We would also like to thank the members of the Program Committee and the additional reviewers for their time and e orts: a special thanks for respecting our deadlines, we know these fell in the middle of the summer holidays for many of you! All abstracts included in this volume have been revised and improved based on your valuable reviews, and we feel the nal result represents a wide variety of topics that will o er a vibrant and exciting session at the conference. Moreover, we would like to thank our local organiser Je He in and Shaku Jain-Cocks for their invaluable help in sorting out the logistics of this track. Finally, we would like to thank Anna Lisa Gentile and Andrea Nuzzolese for their invaluable help to set up the online voting system for the Best Demo/Poster Awards.