The Portugal captain was visibly troubled when he saw two bottles of the carbonated soft drink in front of him as he sat down to speak to the media on Monday in Budapest ahead of his national team's Group F opener against Hungary.
Ronaldo, an advocate of a healthy diet, moved the glass bottles out of the camera frame and instead held up a bottle of water and said in Portuguese: "Water!"
Coca-Cola saw its share price drop by 1.6% to $55.22 soon after Ronaldo's actions. The market value went from $242bn to $238bn -- a $4bn drop.
Coca-Cola, an official sponsor of Euro 2020, responded in a statement that "everyone is entitled to their drink preferences" with different "tastes and needs."
Coca-Cola company has 200 brands worldwide, including different types of water. A Euro 2020 spokesperson said: "Players are offered water, alongside Coca-Cola and Coca-Cola Zero Sugar, on arrival at our press conferences."
They added that without the support of brands like Coca-Cola, "we could not organise a tournament with such success for players and fans, nor invest in the future of football at all levels."
Coca-Cola's partnership with UEFA goes back to 1988 with the company having "a long tradition of supporting all sports at its various levels" and which has allowed "investment in football at all levels."
Pogba, a practising Muslim who does not drink alcohol, removed the bottle when he sat down to speak to the media after he was named man of the match.
On Tuesday, Ronaldo, 36, became the leading scorer in European Championship history with 11 goals. The Juventus forward struck twice in Portugal's 3-0 win over Hungary in what was his record fifth tournament appearance.
The defending champions had to wait until the 84th minute to break the deadlock. Ronaldo later shared a message with his almost 300 million Instagram followers about resilience.
The five-time Ballon d'Or winner wrote: "You have to know how to suffer, fight to the end and always believe with all your strength. There are no easy opponents or games won straight away.
"The European Championship is a luxury stage where only the best of the best are present and where every victory has to be won with all the determination and selflessness. Big win, team!"
Information from Reuters was used in this report.