Mediation vs. Arbitration in Ontario: Which Dispute Resolution Option Fits?

Mediation and arbitration both get grouped under the label “alternative dispute resolution,” and both happen outside a courtroom, with a neutral third party involved. Beyond that, they work in almost opposite ways. Mediation is a voluntary, non-binding negotiation process — the mediator helps the parties talk, but has no power to decide anything for them. Arbitration is the opposite: an arbitrator actually hears the dispute and issues a binding decision, much like a judge would, except in a private setting the parties have usually agreed to in advance.

The distinction matters because the two processes suit different situations. A dispute where both sides are still willing to talk and just need help finding common ground is often a good candidate for mediation. A dispute where the parties fundamentally disagree on the facts or the law, and need someone to actually decide who’s right, is better suited to arbitration — or, if there’s no arbitration clause, to court. This article walks through how each process actually works, how they compare on cost, speed, confidentiality, and enforceability, and when a contract might require one or the other. For a broader view of how contract disputes unfold in Ontario, see our contract disputes hub.

Mediation typically starts with both parties agreeing on a mediator — sometimes named in the contract, sometimes chosen jointly once the dispute arises. The mediator doesn’t investigate or take sides; their job is to facilitate a conversation, help each side understand the other’s position, and explore settlement options that neither side may have considered on their own.

A typical session starts with both parties together, where each side (often through a lawyer, though this isn’t required) briefly explains its position. The mediator then frequently moves to separate rooms, going back and forth between the parties to relay offers, test assumptions, and narrow the gap. This “shuttle” approach lets people speak more candidly than they might in a joint session. Sessions commonly run a half-day to a full day, though complex disputes can take longer or require follow-up sessions.

If the parties reach an agreement, it’s usually written down and signed on the spot, turning it into an enforceable settlement contract. If they don’t, either side is free to walk away and pursue arbitration or court instead, and nothing said during the mediation is generally admissible as evidence later.

Arbitration looks and feels more like a scaled-down trial. The parties (or their contract) select an arbitrator, or sometimes a small panel, who has the authority to decide the dispute. Ontario’s Arbitration Act governs most private arbitrations and fills in procedural gaps the contract doesn’t address.

The process generally includes an exchange of written positions, some form of document disclosure, and a hearing where each side presents evidence and arguments — though arbitration hearings are usually shorter and less formal than a court trial, and the rules of evidence are often relaxed by agreement. After the hearing, the arbitrator issues a written award explaining the decision and any amount owed.

Appeal rights are narrow. Under the Arbitration Act, an award can usually only be appealed on a question of law, and only if the arbitration agreement doesn’t say appeals are excluded — many commercial arbitration clauses say exactly that, making the award effectively final.

Cost. Mediation is typically the cheaper option — often a single mediator’s fee split between the parties, with no lengthy document exchange or formal hearing. Arbitration costs more, since it involves the arbitrator’s fees, a more structured process, and usually legal representation on both sides, though it’s still generally less expensive than a full court trial once legal fees and court delays are factored in.

Speed. Both processes tend to move faster than litigation because the parties control scheduling rather than waiting for court availability. Mediation can often be arranged within weeks; arbitration takes longer because of the hearing and award-writing process, but it’s still typically quicker than waiting for a court date.

Confidentiality. Mediation sessions are generally private and conducted without prejudice, meaning what’s said can’t usually be used later if the matter proceeds. Arbitration hearings and awards are also generally private, unlike a court proceeding, which creates a public record — a meaningful advantage for parties who want to keep the dispute, and sometimes the outcome, out of public view.

Enforceability. This is the sharpest difference. A mediated agreement is only binding once it’s written down and signed as a settlement contract — until then, either party can walk away. An arbitration award is binding from the moment it’s issued and enforceable much like a court judgment, with very limited room to challenge it afterward.

Many Ontario commercial contracts build dispute resolution into their terms from the start. It’s common to see a “tiered” clause requiring the parties to attempt mediation first, and only move to arbitration (or occasionally litigation) if mediation doesn’t resolve things within a set period. Franchise agreements, construction contracts, partnership and shareholder agreements, and many commercial leases often include clauses like this, partly because disputes in those relationships are common enough that the parties plan for them in advance.

Where a contract contains a valid, enforceable arbitration clause, Ontario courts will generally stay (pause) a lawsuit filed in breach of it and direct the parties to arbitration instead, with narrow exceptions in some consumer contexts. Where a contract is silent on dispute resolution, nothing requires either process — mediation and arbitration are then simply options the parties can agree to pursue once a dispute arises, alongside or instead of a court claim.

When a contract doesn’t dictate the process, the choice often comes down to the relationship between the parties and how much they disagree. If the relationship is ongoing or the parties are still talking, mediation is usually worth trying first — it’s lower cost, faster, and preserves the option to escalate if it doesn’t work. If the dispute involves a serious factual or legal disagreement, or one side has stopped engaging entirely, arbitration or a court claim may be the more realistic path, since mediation generally depends on both sides being willing to negotiate in good faith.

Some parties use a hybrid approach sometimes called “med-arb,” where the same or a different neutral first attempts mediation and then, if that fails, moves directly into an arbitration role to decide any issues that remain unresolved. This can save time and avoid repeating the same background explanation twice, though it also means a party needs to be comfortable with the same person wearing both hats — something worth discussing and agreeing to clearly before the process starts, rather than assuming it by default.

It’s also worth remembering that neither mediation nor arbitration prevents the parties from simply negotiating directly, with or without lawyers, at any point along the way. A dispute can move back and forth between informal negotiation, mediation, and arbitration as circumstances change, and reaching a settlement at any stage generally ends the need to proceed further. Where no agreement is reached through any of these routes, a court claim — through Small Claims Court for smaller amounts or the Superior Court of Justice for larger ones — generally remains available as a last resort, subject to any arbitration clause that applies.

A formal demand letter often precedes either process and can sometimes resolve the matter before mediation or arbitration is even necessary. And regardless of which path looks likely, it’s worth checking Ontario’s limitation period for contract claims early, since pursuing mediation or arbitration doesn’t necessarily pause the clock on a court claim unless the contract or the parties agree otherwise. Our tools page also has resources that can help organize the documentation either process will call for.