Do I pay child support with joint custody?

Possibly; it depends on number of factors that are unique to your situation. Court-ordered joint custody of your child does not automatically eliminate the obligation to pay child support.   “Custody” of any type (sole, joint, shared etc.) simply refers to decision-making responsibility; it does not relate to allocating the financial obligations that arise in connection with the important job of raising your child. For that, the federal and Ontario Child Support Guidelines are the first-stop for determining how much child support you may be liable to pay, depending on a number of factors such as your income and that of the other parent.