The IEEE Symposium on 3D User Interfaces 2014 is the ninth international symposium focused on the topic of 3D User Interfaces (3D UI). It provides an unique opportunity for industrial and academic researchers to exchange about the state-of-the-art 3DUI research! The symposium will last for two days, and will be followed immediately by the IEEE Virtual Reality 2014 conference. All areas of 3D UI research will be presented, including: 3D input devices 3D display and sensory feedback 3D interaction techniques 3D user interface metaphors Desktop 3D UIs 3D UIs for VR and AR Evaluation methods for 3D UIs Biologically inspired 3D UIs Human perception of 3D interaction Collaborative 3D interaction Applications of 3D UIs: games, entertainment, CAD, education, etc Researchers can participate in a number of ways, including submitting full technical papers, technotes, and posters. In addition, there will be our annual 3D User Interface competition: the 3DUI Contest.