Osei, 24, has scored 14 goals in 26 appearances so far this season for Stalybridge.
South Shields joint manager Lee Picton said: “We’re delighted to bring Darius into the club.
“We’ve had him watched a number of times this season and he also really caught our eye in our earlier encounters with Stalybridge Celtic this season.
“His skill set is extremely well-rounded and at 24 years of age, we believe we can really help him to develop even further.
“It has been quite a long process over an extended period of time to try to bring him to the club but now we eventually have we couldn’t be happier.
“We’re absolutely positive that he will become a fans’ favourite over hopefully many seasons to come.”
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