Open Data Challenges MulvanyIan 2016 Calls in favour of Open Data in research are becoming overwhelming. They are at national [@RCKUOpen] and international levels [@Moedas2015, @RSOpen, @ams2016]. I will set out a working definition of Open Data and will discuss the key challenges preventing the publication of Open Data becoming standard practice. I will attempt to draw some general solutions to those challenges from field specific examples.