Ancelotti was Kaka's coach at AC Milan when he won the World Player of the Year award in 2007 and Real fans are hoping the Italian will be able to help the player, who cost Real 65 million euros ($85.4 million) and turned 31 in April, to rediscover some of that glittering form.
Kaka's four-year stint in La Liga has been disrupted by injury but when he has played he has looked a shadow of the man who inspired Milan to Champions League success six years ago.
Under Jose Mourinho, who quit Real and returned to Chelsea at the end of last season, he often cut a forlorn figure on the bench, leading to speculation that he might be sold before the transfer window closes at the end of next month.
He made only 12 La Liga starts last term and just two in Europe and one in the King's Cup.
"Kaka is a Real Madrid player like all the others," Ancelotti said on Saturday in his first news conference since the players returned to training this week.
"He has started work well and it is clear that he has a lot of confidence for this season and a lot of motivation," the 54-year-old added.
"Later we'll see what happens. Kaka is a player with a lot of character and he wants to do better than last season."
Ancelotti's relaxed and good-humoured appearance before reporters was a refreshing change from the ill-tempered affairs hosted by Mourinho last season.
The Italian, who has also coached Chelsea and Paris St Germain, drew laughter when he listened to a lengthy question in English before announcing that he had not understood a word.
He gave little away about whether Real will add more players to the squad, brushing off enquiries about whether the club were interested in Tottenham Hotspur's Wales winger Gareth Bale or PSG's Sweden striker Zlatan Ibrahimovic.
Ancelotti has Zinedine Zidane working as his number two and he praised the former France and Real midfielder's contribution.
"He is very motivated and has a lot of desire to learn," Ancelotti said of Zidane, who recently earned his coaching qualifications.
"I think he's good for us because he has a very good relationship with the players and they will listen to him a lot. I think he will help the team to be better."
Real play their opening pre-season friendly on Sunday at English second-division side Bournemouth.