Wren will join the MoD in the New Year, replacing Nick Gurr, who leaves at the end of the year to take a policy-focused role.
Wren said: ‘I am delighted to be appointed director of media and communication at the MoD and will be joining another first rate government communications team early in the New Year.
‘Dealing with the ongoing operations in Afghanistan alongside the implementation of the Strategic Defence and Security Review will clearly be my top communication priorities.’
Wren was the MoD’s head of news for nine months between 2005 and 2006. After that, he moved to the Home Office, where he took the same role.