The 22-year-old joined the Latics in 2016 from then-National League North neighbours Stalybridge Celtic, but has found opportunities limited.
He scored two goals in the EFL Trophy last season against Carlisle United and scored against Blackpool earlier this season.
But following a change of management at Boundary Park and a desire for more game time, Osei has agreed terms with the Stones – signing a deal until the end of this season.
Maidstone manager Jay Saunders told his club`s official website: “I am delighted to get Darius on board. He’s a versatile forward who gives me options in wide positions and down the middle”.