This volume contains the proceedings of the Ninth IFIP WG 6.1 International Conference on Formal Methods for Open Object-Based Distributed Systems (FMOODS 2007). The conference is part of the federated conferences on Distributed Computing Techniques (DisCoTec), together with the Ninth International Conference on Coordination Models and Languages (COORDINATION2007) and the Seventh IFIP International Conference on Distributed Applications and Interoperable Systems (DAIS 2007). It was organized by the Department of Computer Science of the University of Cyprus, and it was held in Paphos, Cyprus during June, 6-8, 2007. The event was the third federated DisCoTec conference series, initiated in Athens in June 2005 and continued in Bologna in June 2006.