Onana was exiled from camp after falling out with manager Rigobert Song during the 2022 FIFA World Cup in Qatar.
The 27-year-old, who has 34 caps for the Indomitable Lions, started their 1-0 defeat to Switzerland in their opening World Cup game before clashing with Song over his playing style.
Onana preferred to play out from the back as evidenced by his 26 touches outside the box against the Swiss but Song wanted a less risky approach.
The former Ajax and Inter Milan goalkeeper announced his retirement after the tournament but will be back for Cameroon's crucial final Africa of Nations qualifier against Burundi next month.
Cameroon need to avoid defeat to book their place at next year's tournament to be hosted in January and February by Ivory Coast.
Speaking in a news conference after revealing Onana's recall, Song said: "There were never any problems. I said at the last [news] conference that it was all up to him and he knew what he had to do.
"If he is on the list, it is because he did the right thing. He is one of the best goalkeepers. The door was always open, it is better to have all these players there than not to have them.
"There were never any problems with Andre and, as I said, he was the only one who knew what he had to do and we are satisfied that he joins the group and we really count on everyone."
