The incident happened on South Service Road, just west of Dewitt Road. Hamilton Emergency Services responded to a single-vehicle collision involving a Honda Civic around 9:48 p.m.
The driver, a 35-year-old man, was pronounced dead at the scene, according to police. His passenger, a 26-year-old woman, was transported to hospital where she later died.
"At this time, speed and alcohol are being consider to be contributing factors in the collision," acting Staff. Sgt. Marco DelConte said.
South Service Road was closed in both directions between Dewitt and Green roads for six hours. It reopened early Saturday morning.
Police are not releasing the names of the victims, as they are still trying to notify the victims' family members, DelConte said.
The deaths are Hamilton's 14th and 15th traffic fatalities of 2014.
Hamilton police's collision reconstruction unit will conduct the investigation into this crash. Anyone who may have information are asked to contact Det. Const. Ben Paterson or Det. Const. Wes Wilson at 905- 546-4755.