The 21st International Conference on "High Magnetic Fields in Semiconductor Physics", HMF-21, will be held in Panama City Beach – Florida, USA, 3-8 August 2014. It is one of the satellite meetings to the 32nd International Conference on the Physics of Semiconductors (32nd ICPS 2014), which will be held in Austin Texas, USA, a week after the HFM-21. HMF-21 follows a series of biennial events initiated in 1972, in Würzburg, Germany. In the past fourteen years, HMF was held in: Matsue, Japan (2000); Oxford, UK (2002); Tallahassee, USA (2004); Würzburg, Germany (2006); São Pedro, Brazil (2008); Fukuoka, Japan (2010); Chamonix Mont-Blanc, France (2012). HMF-21, co-organized by the National High Magnetic Field Laboratory and Georgia Institute of Technology, will be a forum for the interdisciplinary, both theoretical and experimental, discussions of the electronic, optical and magnetic properties of semiconductor- and carbon-based structures and materials, with particular emphasis on research in high magnetic fields.