Yes and no - most any hotshoe mount flash will physically fit in there, but only sony specific ones will work with the camera's metering properly, and what's more is you risk damaging the camera as some (typically older) flash units will put a high voltage across the terminals when triggered.
Sony and Minolta hot shoes have the iISO hot shoe and electrical contact layout and won't work with speedlights having the standard ISO 518:2006 foot and electrical contact layout, unless as mentioned an adaptor is used between an ISO 518:2006 speedlight and the odd-ball Sony/Minolta iISO hot shoe.