25-year-old Osman has become Steve Davis's fifth signing of the season as the Railwaymen look to start strong in League One.
Davis has already snapped up Mark Ellis (Torquay United), Gregor Robertson (Chesterfield) Mathias Pogba (Wrexham) and Michael West (Ebbsfleet) during the close season as he looks to strengthen the squad ahead of the start of the season.
Osman had been on Crewe's radar a few years back and spent 3 years at Northampton Town from 2008-2011 and last season spent a full season at Greek side Kerkyra.