What kind of training does a person require, to become a Wedding Officiant, in Ontario, Canada?

Either a law degree, a seminary degree, or a degree in public or business administration; and subsequent job experience as one of:

a judge or justice of the peace (this is what the law degree gets you started toward), or

a priest, pastor, rabbi, imam or other cleric in a religious body recognized by the government of Ontario, or

a municipal clerk.

Sorry, but Ontario doesn't have generic wedding officiants. Civil marriages are performed only by judges or justices of the peace, or by municipal clerks. Religious marriages are performed by recognized clerics.

Google York St. Peter's Evangelistic Organization. In order for clergy to be registered with the Office of the Registrar General to perform a wedding legally, they must be a member of a recognized Religious Denomination who will recommend them to receive registration. York St. Peter's Evangelistic Organization is a registered and recognized Religious Denomination in Ontario and has been around for 47 years. They provide training, workshops, practical experience and they can sponsor you to the Registrar General to receive your registration in Ontario to perform weddings in your own church pending training and evaluation. If you are not ordained but have a sincere calling to preach the Gospel of Jesus Christ, an active congregation and the desire to grow your church YSP can help too. They are based out of Toronto.