In Ontario is a deposit necessary to make a binding Agreement

Great question! It is my understanding that technically no deposit is required in order to make a binding agreement. However, providing a deposit is considered a sign of good faith. I would expect that most Sellers would become suspicious or at least concerned to receive an Offer with no deposit. In most cases there is no reason for the deposit to be excessive but should be enough to show that you are sincerely interested in the property. The deposit is usually not required until an agreement has been reached and should be held in trust to be applied to the purchase price upon closing.

There is no legal requirement to provide a deposit to create a binding agreement, but if you were selling your home would you want a deposit from the buyers who are putting in an offer?
Providing a deposit shows the sellers that you are a serious buyer.

Legally speaking, no deposit is required. The standard Agreement of Purchase and Sale has a seal on the signatures page. This means both the buyer and the seller 'sign under seal' which is legally binding. Realtors should be explaining what this means to their clients when they sign.
However, most sellers would not accept an offer without a deposit.

Technically no, but it is in your best interest to do so, since the Seller will probably not be comfortable without a deposit.

The Agreement is Binding to whatever the parties agree to; so the deposit is not necessary, but usually requested by the Seller, who might not agree to an agreement without the deposit.

Explaining the fact they are signing under seal makes the agreement legally binding. It would certainly be very poor neogociating on the buyers part to not include a deposit

If you want to show the motivation you need the deposit. Normally $5000. If you add little more on top of that, while there are multiple listings, the seller might consider to negotiate with you.

You are not required to deposit any money still you can send as I said chances would be slim to consider for negotiation.

No deposit is needed for an Agreement to become binding. Deposit benefits both parties, it is a symbol/proof of good faith that could be considered in a potential legal dispute if the Seller or Buyer attempts to breach said contract. Also it could serve as an enticement for a better deal.