Can a court override our separation agreement in Ontario?

Courts in Ontario have the authority to set aside or vary a separation agreement in certain situations, though they generally respect agreements that were freely and fairly made.

A court can set aside the entire agreement if it was signed without adequate financial disclosure, if one party did not understand the agreement, if one party signed under duress or undue influence, or if the agreement is unconscionable — meaning so one-sided that it shocks the court's conscience.

Courts can vary specific provisions regardless of the parties' agreement on two topics: child support and parenting. Child support is the child's right, and courts can change it whenever the amount deviates significantly from what the Child Support Guidelines would require, or when there has been a material change in circumstances. Parenting arrangements can be changed if a material change in circumstances warrants it and the change is in the best interests of the children.

Spousal support is more durable — if both parties freely agreed to terms with independent legal advice, courts are more reluctant to interfere unless the change in circumstances was drastic.

This means that while separation agreements are binding, they are not completely immune from court scrutiny.