In Ontario, some mediation services are free, but for the most part it is something you and your ex would have to pay for yourselves.
Firstly, there are free mediation services provided at courthouses across the province, through on-site Family Law Information Centres. On the day of your hearing before the Family Court judge, these centres provide free on-site mediators to help you and your ex try to resolve some of your issues.
Also, if you and your ex meet the financial and other eligibility requirements for participating in mediation through the provincially-funded Legal Aid Ontario program, then you may not have to pay, or may be allowed to pay a sliding-scale fee, depending on your income eligibility and how many dependents you have.
Otherwise, any mediation that you and your ex may undertake will have to be privately-funded, since those services are not covered by the province. Private mediators charge varying fees, based on either an hourly rate or flat-fee.