The surprise decision was made at the body's executive committee meeting in the Moroccan capital and announced at a press conference by CAF President Patrice Motsepe.
The tournament, which brings in an estimated 80% of CAF’s revenue, has traditionally been held every two years since its inception in 1957.
Sunday marks the start of the 35th edition, hosted in Morocco with the home team taking on Comoros.
Motsepe said the next Cup of Nations finals, scheduled for 2027 in Kenya, Tanzania and Uganda, will go ahead and then another tournament would be held in 2028, but after that, it will be hosted every four years.
Motsepe announced the launch of an African Nations League annually from 2029 to fill the gap, following the example of Europe, which holds its championship every four years.
“Historically, the Nations Cup was the prime resource for us, but now we will get financial resources every year," he said.
“It is an exciting new structure which will contribute to sustainable financial independence and ensure more synchronisation with the FIFA calendar.”
Holding the Cup of Nations every four years had been previously proposed by FIFA President Gianni Infantino but this had been rebuffed by CAF because of their reliance on the revenues that the tournament generates.
The timing of AFCON has long courted controversy because it has usually been hosted in the middle of the European season, forcing clubs to release their African players.
This tug of loyalty was supposed to be solved by moving the Cup of Nations to mid-year from 2019 but later tournaments in Cameroon in 2022 and Ivory Coast in 2024 were again hosted at the start of the year.
This year's tournament in Morocco was moved back six months when FIFA introduced a new-look Club World Cup, which was hosted in the US in June and July.
