Pierre Francois Aubameyang, 53, captained Gabon to their AFCON bow in 1994 and played over 200 professional fixtures in the French league.
Cousin, 41, formerly of Hull City and Glasgow Rangers played in France and Greece, scored 13 goals in 53 appearances for his country and represented them at the 2000, 2010 and 2012 Nations Cups.
They are both expected to fill the role made vacant following the departure of Spanish coach Jose Antonio Camacho at the end of his contract.
According to the nations football federations (Fegafoot), Aubameyang and Cousin will have equal roles in the new set-up with a target of reaching the 2019 AFCON showpiece.
"Therefore, we have as national coaches, Pierre François Aubameyang and Daniel Cousin, while Françols Amegasse will act as General Manager.
"These three former captains of the national football team deserve, with their strong knowledge on the field and experience of top-level competitions, to transmit their experience and tactical abilities to the team."
The first competitive games for the duo are in mid-October, with back-to-back 2019 qualifiers against South Sudan.