The South Korean will move to Signal Iduna Park on a free transfer at the end of the season, having signed with Augsburg earlier this week
The South Korea international only sealed a permanent move to the Bavarian club earlier this week from Sunderland on a short-term deal, having enjoyed a spell at the SGL Arena last season.
However, his time back at the club will be shortlived as he will join BVB on a free transfer on July 1.
"Ji can play in various positions across the front line," sporting director Michael Zorc told the club's official website.
"We are happy to have signed this talented player on a free transfer for next season."
Ji first moved to Europe from Chunnam Dragons back in 2011 and has won a total of 26 caps for his country.