The Germany international has moved to Westfalenstadion on a deal set to run until the end of the season, at which point Dortmund are obligated to purchase him outright for €30 million (£25m/$33m) if certain conditions are met.
With Euro 2020 just around the corner, Can has joined BVB in search for regular football, after being restricted to just eight Serie A appearances for Juve this season.
“I think the team has great potential and can win something,” The 28-year-old told the media at his official unveiling on Friday afternoon.
“I am convinced that I can help them and can’t wait to play in front of these fans for whom Borussia Dortmund is known all over the world for the first time.”
BVB sporting director Michael Zorc added: “In Emre Can we get a German national player who can be used across multiple systems in defence as well as in central midfield.
“A player who brings in his technique as well as his technique and has a strong will to win.”