Typically, this will expedite the process from being over 10-15 weeks to a min of 3-6 weeks. The entire process of how to get married in Ontario is explained here. A sample letter to go with your marriage licence is here and a sample letter to fax to the Registrar after you have applied for your certificate online is here.
In cases of urgency, here are your options:
Expedite the processing of your Marriage Licence:
(UPDATED since the video above was posted.) Apply for your certificate online here. Yes, that's right, apply for your marriage certificate before you are even married. You will get the tracking number at the end of the application process to go in your letter with your licence.
Bring the following items to your Officiant:
Your licence from City Hall, (application for the licence here)
A letter stating your urgency for expediting your marriage licence and certificate (copies of any supporting documents: airline tickets, invitations, letters).
In that letter, state your Licence Number (Starts with a G and is at the top of your licence) and the tracking number from applying for your certificate (online here).
A pre-paid Express Post envelope. (Not Priority envelope, as it goes to a postal box and no one can sign for it).
Your Officiant is the only person who can send your marriage licence to the Registrar. They cannot let anyone else send the licence. The Registrar in Thunder Bay will get the Express Post envelope, and they will determine the validity of your need to expedite your forms.
Expedite the processing of your Marriage Certificate.
You will need to fax the a letter (practically the same letter but without the request to expedite the licence) requesting to expedite the processing of the certificate with any supporting documents again to one or all of these numbers:
Emergency Fax # 807-343-7445 e.g. Facing deportation immediately, sudden illness
Urgent Fax # 807-343-7459 e.g. Request to expedite the certificate quickly
Marriage Office Department # 807-343-7284 e.g. The actual Registrar's Office, but the faxes received here are not treated with urgency.
The trick is to know if your letter, attached to the marriage licence was successful in expediting its processing.Therefore call 1-800-461-2156 to inquire into your marriage licence processing. They may have already sent you the certificate if your licence was processed. But if not, the people at this number will give you the specific fax number for the department addressing your issue, such as immigration.