The 1,500-strong battalion will be trained in 'manipulation through social media' before formally launching on 1 April. The army hopes the brigade will help to influence the opinions and behaviour of the enemy and local populations.
About half of the soldiers are reservists, with the rest recruited from the army, navy and Royal Air Force (RAF).
The unit will be known officially as the '77th Brigade', which was also the name for the 'Chindits', a Second World War special force that conducted guerrilla raids behind Japanese lines in Burma.
The brigade will focus on 'unconventional' non-lethal military methods such as "shaping behaviours through the use of dynamic narratives" to meet "the challenges of modern conflict and warfare", according to the Army.
It will draw "heavily on important lessons from our commitments to operations in Afghanistan amongst others", a spokesman said.
As well as explicitly learning from counter-insurgency operations in Afghanistan, the launch of 77th battalion is also seen as a reaction to methods deployed by Islamic State, Russia, North Korea and other nations or groups.
It is part of a wider 'Army 2020' plan to reduce the size of the regular Army from 91,600 in 2013 to 82,000 regular troops by 2017 and recruit at least 11,000 reserve soldiers to help meet the shortfall.
The brigade will be located at Hermitage, Berkshire, with soldiers operating at other MoD sites. It will operate across all armed forces and work with Whitehall departments plus other nations.
Image credit: Crown Copyright 2013 / Cpl Ross Fernie RLC