Both teams won their domestic leagues this season, with Madrid taking the La Liga title away from Barcelona, while Juve made it six Serie A titles in a row.
"We're very happy to be in the final," said Madrid boss Zinedine Zidane. "We know how difficult it is to get there and we've worked very well during the year.
"We deserve to be in the final and the team is going in to it in very good physical shape and we're confident."
Los Blancos are making a habit of appearing in finals of late, having finally won La Decima in 2014 before capturing their 11th title last season. Juve last appeared in the 2015 final in Berlin, when they lost 3-1 to Barcelona.
"Juventus haven't lost six finals, we've been involved in eight! Making the final is incredible," said Juve manager Massimiliano Allegri.
"There's only one Champions League like there's only one Superbowl and what matters is being in the right place at the right time.
"I'm delighted to be in the final and I feel fortunate to be leading a team out in Cardiff on Saturday."
The big team news for Real is that Gareth Bale is fit enough to feature having recovered from a calf injury that has kept him out of action since April.
The Welshman could therefore feature, and would be cheered by the local crowd in his hometown, but his lack of match fitness means that Isco is more likely to be given the nod.
For Juve, the only expected absentees are winger Marko Pjaca and centre-back Daniele Rugani, although neither are starters in Allegri's prefered XI, and the Italian will otherwise have a full squad to choose from with Mario Mandzukic and Sami Khedira seemingly fit despite injury scares.