The 29-year-old, who has 18 months left on his current deal, had been linked with Everton and Fulham.
De Camargo has played nine times for Belgium since gaining citizenship in 2009.
He previously played for Belgian sides Genk, Beringen-Heusden-Zolder, FC Brussels and Standard Liege, before moving to Monchengladbach in 2010.
Hoffenheim are currently struggling in the Bundesliga and are 17th in the 18-team league with only 13 points from 19 matches.
General manager Andreas Muller said: "De Camargo will bring more impact in offence. I'm certain that he will play an important role for us with his class and experience."