This book constitutes the refereed proceedings of the 9th IFIP WG 11.11 International Conference on Trust Management, IFIPTM 2015, held in Hamburg, Germany, in May 2015. The 10 revised full papers and 5 short papers presented were carefully reviewed and selected from 28 submissions. In addition, the book contains one invited paper and 5 papers from a special session on trusted cloud ecosystems. The papers cover a wide range of topics including trust and reputation and models thereof, the relationship between trust and security, socio-technical aspects of trust, reputation and privacy, trust in the cloud and behavioural models of trust.