Pam Teare takes the new role on 3 May. She replaces Clare Harbord, who is moving on to a role in the private sector, the details of which have not been revealed.
While in a previous job as director of news at the Ministry of Defence, Teare was a key witness in the Hutton inquiry, having been the author of the Q&A briefing that led to the naming of Dr David Kelly.
Teare said: ‘I'm really looking forward to starting this new challenge at the MoJ - a department with a constantly high profile and one which deals with a wide variety of very important issues.’
The new role has been expanded and now encompasses comms, correspondence, information management and data requests.
There will be a short handover period as both Teare and Harbord work in the comms department at the same time.
Last November, the MoJ appointed the Home Office's deputy news chief to be head of news. Scot Marchbank took up the new role in January, replacing Vickie Sheriff, who is now head of news at 10 Downing Street.
All government departments have been handling their own reviews of senior civil service positions since October, leading to suggestions that the existence of director of comms positions at key government departments is at risk.