The Internet has made it easier to perpetrate crimes by providing criminals with an avenue for launching attacks with relative anonymity. The increased complexity of the communication and networking infrastructure is making investigation of cyber crimes difficult. Clues of illegal activities are often buried in large volumes of data that need to be sifted through in order to detect crimes and collect evidence. The investigations are increasingly cross-border requiring coordinated police efforts in different jurisdictions. This volume contains papers presented at the Third International ICST Conference on Digital Forensics and Cyber Crime (ICDF2C 2011), held October 26–28, 2011 in Dublin, Ireland. Unlike other conferences in the field of digital forensics, ICDF2C focuses on the applications of digital forensic research, providing a forum where practitioners can learn how the latest research results can be used in everyday investigations of cyber crimes and corporate misconduct. The 24 papers contained in this volume cover a variety of topics ranging from tactics of cyber crime investigations to digital forensic education, network forensics, and the use of formal methods in digital investigations. There is a large section addressing forensics of mobile digital devices. Each paper was reviewed by a minimum of three members of the Technical Program Committee. We sincerely thank the Technical Program Committee for their hard work in reviewing the submissions. We thank the Organizing Committee, Nasir Memon, Felix Balado, Fergus Toolan, Michael Harris, Bernhard Otupal, Ibrahim Baggili, Avinash Srinivasan, Cormac Doherty, and Joshua I. James, for their tireless efforts in managing all of the arrangements required for a successful conference. Finally, we offer special thanks to Anna Sterzi, Elena Fezzardi, and all the staff at EAI who made this conference possible.