The Inter Milan star, 26, was sent home from the tournament in Qatar following a blazing row with manager Rigobert Song, who reportedly took issue with his goalkeeping style.
Song clashed with Inter Milan shot-stopper during training for taking too many risks with his feet, sparking a shouting match between the pair. Leaked footage later showed the head coach explaining what was said during the dispute.
He claimed his goalkeeper became tearful after approaching him to discuss his displays and that he avoided speaking to him.
Onana has now made the decision to step down from international duty altogether, confirming his Cameroon retirement in a lengthy post on social media.
He wrote: ‘It all started in Ngol Nkok, a small village where, from a very young age, my family passed on to me the values that identify the Cameroonian people. I understood that love for this country is eternal and that commitment is non-negotiable.
‘I remember how we watch the matches as a family. Only Cameroonians can understand what it means to us to see the Indomitable Lions play. That’s when I started dreaming of one day wearing the national team jersey.
‘And now, after endless hours of training, endless trips and a lot of perseverance, I can proudly say that I have fulfilled my great dream.
‘But every story, however beautiful it may be, has its end. And my story with the Cameroonian national team has come to an end.
‘Players come and go, names are fleeting, but Cameroon comes before any person or player. Cameroon remains eternal and so does my love for the national team and for our people who have always supported us no matter how difficult the moment was.
‘My feeling will never change. My Cameroonian heart will continue to beat and wherever I go I will always fight to lift the flag of Cameron [sic] as high as possible.
‘I will continue to support as a fan, just as the more than 27 million Cameroonians do at every match. I can only thank all those who trusted me and believed that I could add and contribute to this team.’
Onana earned 34 caps during his six-year Cameroon career, helping them secure a third-place finish at last year’s Africa Cup of Nations.