2001-JAN-14: Two same-sex couples were married in a church service in Toronto. Kevin Bourassa & Joe Varnell, and Anne & Elaine Vautour could not obtain marriage licenses from the Province of Ontario. Thus, they had gone through through the ancient ritual of the reading of the banns. Their upcoming marriages had been previously announced in church on three consecutive Sundays. This can be done instead of purchasing a marriage license. After they were married, the Ontario government refused to register their marriages. However, two and a half years later, on 2003-JUN-10, the Ontario Court of Appeal retroactively recognized the marriages, thus making Kevin and Joe the first same-sex couples in the world -- at least in recent centuries -- to be have been legally married!

The certificate of marriage for the first gay marriage
solemnized in modern times was Ontario License, #M555228.

Three months later, the first same-sex couple in the world to go through the normal procedure of obtaining a marriage license, subsequently marrying, and then registering their marriage were living in the Netherlands.
 

2005-JUL-20: Bill C-38, which theoretically made same-sex marriages available across Canada was signed into law by the Chief Justice of the Supreme Court of Canada. Normally, this action is taken by the Governor General. However, she was incapacitated by a medical problem. Same-sex couples anywhere in Canada could theoretically be married.

A decade later, minus 24 days, the U.S. Supreme Court issued a ruling in Obergefell v. Hodges. It legalized gay marriage everywhere in the U.S. except for Territory of American Samoa. Most people in that territory are considered American residents, not American citizens. Thus, the High Court rulings do not neccesarily apply there.