Obeng began last season at Winchester City, before going on to feature for AFC Totton then return to former club Brockenhurst FC, who play in the Wessex Premier League.
He will add a new dynamic to the Bees' frontline as they look to mount another play-off push, having finished two points and three places adrift of the top five in 2022/23.
Manager Mitch Austin said: "We've know Silvano for a long time and I'm pleased to reunite with him.
"He will be such a force up front for Harborough Town. In the year we were promoted, Silvano, was scoring over 40 goals for Brockenhurst FC at Step 5 and last season played at Step 3 level for Winchester City.
We cannot wait for the start of pre-season matches and then get the season started!"