Assistant Chief of the Naval Staff

The Assistant Chief of the Naval Staff (ACNS) is a senior appointment in the Royal Navy. The incumbent is in practical terms the deputy to the head of the Royal Navy, the First Sea Lord.

The ACAS post was established in 1985 by eliminating the Vice-Chief of the Naval Staff and combining the Policy and Operations two star assistant chiefs. The ACNS is a member of the Admiralty Board.

In April 2012 Rear Admiral Matthew Parr's post as Assistant Chief of the Naval Staff was re-designated Assistant Chief of the Naval Staff (Policy) and the former Chiefs of Staff responsible for Capability, Support, Aviation & Carriers and Personnel were also re-designated Assistant Chiefs of the Naval Staff.

Assistant chiefs of the naval staff
These have included: Assistant Chief of the Naval Staff Assistant Chief of the Naval Staff (Policy)
 * 1985 - 1986 Rear-Admiral Jeremy Black
 * 1986 - 1988 Rear-Admiral Michael Livesay
 * 1988 - 1991 Rear-Admiral Hugo White
 * 1991 - 1993 Rear-Admiral Peter Abbott
 * 1993 - 1995 Rear-Admiral John Brigstocke
 * 1995 - 1997 Rear-Admiral Jeremy Blackham
 * 1997 - 1999 Rear-Admiral Jonathon Band
 * 1999 - 2001 Rear-Admiral James Burnell-Nugent
 * 2001 - 2003 Rear-Admiral Timothy McClement
 * 2003 - 2005 Rear-Admiral Adrian Johns
 * 2005 - 2008 Rear-Admiral Alan Massey
 * 2008 - 2009 Rear-Admiral Robert Cooling
 * 2009 - 2011 Rear-Admiral Philip Jones
 * 2011 - 2012 Rear-Admiral Matthew Parr
 * 2011 - 2013 Rear-Admiral Matthew Parr
 * 2013 - Rear-Admiral Clive Johnstone