The 24-year-old central defender arrives at Elland Road as manager Marcelo Bielsa’s eighth summer signing for an undisclosed fee.
"Leeds United are pleased to announce the signing of Robin Koch from Bundesliga side SC Freiburg for an undisclosed fee," the Whites revealed in a statement published on the club's official website on Saturday.
"The 24-year-old has signed a four-year deal at Elland Road, running until the summer of 2024."
Koch made 32 appearances last season in the Bundesliga for Freiburg, who finished eighth on the table.
Koch told LUTV: "Marcelo Bielsa was one of the main points for me to join Leeds, I've heard from everybody he is one of the best coaches and I'm really looking forward to the first session with the team and the coach.
"Leeds is such a big club and after winning the second league last year, Leeds are back."
He added: "I've played three years in the Bundesliga which is also a big league, but I think the Premier League is the next step for me."
Koch has won two caps for the German national team and has been called up for once again for Nations League matches against Spain and Switzerland next month.
Leeds broke their transfer record to sign 29-year-old Spain international striker Rodrigo Moreno from Valencia earlier on Saturday.
Leeds United are back in the Premier League after a 16-year hiatus and will take on champions Liverpool in the opening weekend of the season.
