Olsey, who has been the acting chief since Sept. 16, will take over for former Chief Anthony Marraccini who retired shortly after being suspended after he was accused of taking paid time off he wasn't entitled to.
Detective Derka Abbat said the promotions will take place at 7 p.m. at City Hall.
In addition to naming a new captain, the board is also expected to promote Lt. Edward Detlefs to captain, a position that has been empty since Marraccini was named chief in 2010, as well as promoting Sgt. John Vasta to lieutenant, she added.
Click here to follow Daily Voice Harrison and receive free news updates.