The Everton defender says Giroud is ahead of Suarez and Aguero as the toughest striker he has faced in his career so far.
The two players have come up against each other a number of times in the Premier League during recent seasons, with the Frenchman enjoying greater success during their last meeting at the Emirates in October.
Despite heading home the first goal of Euro 2016 for France on Friday, Giroud continues to divide the opinions of many fans, particularly those in North London, who have seen the striker turn in some largely disappointing recent performances.
Explaining his decision he told Mundial: “I mean they [Aguero and Suarez] are great players, with unbelievable movement. In all honesty, I’d have to say Olivier Giroud, you don’t realise how strong he is.
“When he gets close to you he can hold you off and his touch is brilliant.”
Despite his recent performances for Everton coming under increased criticism, Stones is still largely seen as one of England's brightest young players, a reputation that has seen him heavily linked with a move away from Goodison Park this summer.