The 29-year-old joins the 2. Bundesliga side from SC Freiburg after making only seven appearances in the Regionalliga last season.
Kyereh's season was cut short by injury, but he has worked his way back to full fitness. He reunites with head coach Timo Schultz after the pair previously worked together at St. Pauli.
Osnabruck started their new campaign with a 4-3 defeat to Heidenheim and the new signing is expected to be in contention for a place on the bench for the league clash with Magdeburg on Saturday.
"These last few years have been very difficult for me," explained Kyereh on Africa Soccer.
"I never lost hope of returning to the pitch. VfL Osnabruck gave me a great deal of support, took my situation and my current status into account. This trust means an enormous amount to me.
“I know Timo Schultz from our successful time working together at St. Pauli and I know how he sees football.”
Schulz added: "Through our time working together, I know how exceptional Kofi (Kyereh) is, both as a footballer and as a person. The last few years have undoubtedly been extremely difficult for him.
"I am therefore all the happier that we are working together again."
