The 29-year-old Brooks signed a deal through June 2024, Hoffenheim said Thursday in a statement.
Kicker magazine reported Hoffenheim paid €300,000 ($327,000) for the transfer.
"I'm delighted to be returning to the Bundesliga,'' Brooks was quoted as saying. "I know both the league and TSG [Hoffenheim] very well, and am highly motivated to get started straightaway and do my bit to help us get back on the path to success in the short term.''
He came through Hertha's youth system and made 29 second-division appearances as he helped the team clinch promotion in 2013.
Brooks joined Wolfsburg in a record transfer for an American player in 2017.
Brooks only made five appearances after joining Benfica last September.
He was unable to force his way back into contention for a spot on the United States' World Cup squad.
He was dropped by coach Gregg Berhalter after appearing in two of the first three qualifiers and has not been selected for the national team since.
Hoffenheim has been struggling lately and has not won any of its last seven games.
"Jay is a seasoned, tough-tackling and aerially strong defender who really needs no further introduction,'' Hoffenheim sporting director Alexander Rosen said. "He should and will contribute to improving our defensive stability with his experience, his vision and his presence.''