Different provinces differ on what the minimum working age is. (See this list here for more info). In Ontario, anyone aged 14 or over can legally be employed, though there are many restrictions as to what types of jobs you can work in: 

According to the Government of Ontario, the following restrictions apply to those under the age of 19, though workers of any age should take care to stay safe in any workplace.

14 years or over:

•  to work in general industrial establishments, such as:

  1. • offices

     • stores

     • arenas

     • restaurant serving areas

15 years or over:

•  to work in factories, other than a logging operation, such as:

  1. • manufacturing or assembly plants

     • repair shops

     • restaurant kitchens

     • automotive service garages

     • produce and meat preparation in grocery stores

     • shipping and receiving areas in grocery stores

     • laundries (for example in a public hospital or a hotel)

     • warehouses

16 years or over to work in:

• a mining plant or surface mine, excluding the working face

• construction, excluding the role of shaft attendant for a shaft where a hoist is being used

• a logging operation

18 years or over to work:

• in an underground mine or at the working face of a surface mine

• in window cleaning

• offshore on or from an oil or gas rig

19 years or over to be a:

• shaft attendant for a shaft where a hoist is being used on a construction project