And the answer ... well, it depends on what type of work you do and where you live.
Unless the industry is federally regulated (e.g. shipping), the age minimums are decided upon at the provincial level.
So for example, you have to be at least 15 years old to work in a factory in Ontario. Conversely, you have to be at least 16 years old to work in a hotel or restaurant in Nova Scotia.
If you're unsure as to what the guidelines are for your province, there's an excellent guide available to download on the Youth.gc.ca website. It contains a province by province breakdown of the minimum age requirements under various employment and occupational standards legislation.
However, federal and provincial legislation are not the only factors that affect the minimum age to work. There are also other private actors that impact how old you have to be.
For example, in the retail sector, most stores require that employees be at least 16 years old. Generally speaking, this is not a retailer-imposed rule; however, in order to be bonded, or insured to handle cash, most insurance policies require that employees be at least 16 years old.
Of course, rules vary from store to store. When I was 15, I worked in a coffee store and handled cash often. Yet when I was hired to work at a clothing store, I couldn't work at the cash wrap desk as I was not of age.
So, as a general rule of thumb, refer to the guide to see if there are any government-mandated age minimums. If they are not, then you will have to ask the employer if they, or a non-governmental entity (e.g. insurance company) have any minimum requirements.
To read the guide and see what the minimums are in your province, click here.