I am a Canadian citizen and my spouse is not. Can my spouse work in Canada?

It depends on the immigration status of your spouse. If your spouse or common-law partner is a permanent resident, they can work in Canada.

If your spouse or common-law partner is in Canada on a temporary resident (visitor) visa, they have to apply for a work permit to be able to work.

Your spouse or common-law partner can apply for a work permit from inside Canada if:

they have a temporary resident permit that is valid for six months or more; or
they have applied for permanent residence under the Spouse or Common-law Partner in Canada – archived class; or
they are eligible to apply for a work permit supported by a Labour Market Impact Assessment (LMIA) – an authorization from Employment and Social Development Canada an employer needs to hire a foreign worker; or
they are eligible to apply for a work permit based on an exemption from the LMIA process.