The son was pulled over just before 1 a.m. on Sunday, in Innisfil, Ont., for speeding.
South Simcoe Police allege the 27-year-old Newmarket, Ont., man failed a roadside screening test and was subsequently charged with impaired driving.
When his mother came to pick him up at the police station later Sunday, an officer allegedly smelled alcohol on her breath and she was given a breathalyzer test that she failed.
Police say she has also been charged with impaired driving.
Both the mother and her son have had their vehicles impounded. They have each had their driver’s licences suspended for 90 days as well.
The mother and son are due to appear in court next month.