Addo is to take over the reins permanently in May but will take charge of friendlies against Nigeria and Uganda in Morocco this month having led Ghana at the World Cup in Qatar.
He combined his post in Qatar with his role as a talent scout for Borussia Dortmund, who have now agreed to release him from his contract to lead the national team on a full-time basis.
"There were some brilliant individuals among the coaches who applied for the job," Ghana Football Association president Kurt Okraku said in a statement.
"Otto was exceptional in the interview process and was rated highly by the search committee."
Addo took over as coach of Ghana in February 2022 when the Serb Milovan Rajevac was sacked. They beat South Korea at the World Cup but finished bottom of their pool and he left immediately afterwards.
"It wasn't easy for me to make this decision, but I'm very grateful and happy that those responsible at Borussia Dortmund are allowing me to take this step," Addo said.
"I've already gained a lot of experience in my role as interim coach (in 2022) and I'm looking forward to the task that lies ahead of me."
His immediate goal will be to get Ghana's 2026 World Cup qualification campaign back on track.
They beat Madagascar 1-0 in their opener but lost by the same scoreline to Comoros. Only the top side in the six-team pool automatically qualifies for the finals.
Ghana are scheduled to be away to Mali and home to Central African Republic in their next two qualifiers in June.
