To date, 15 countries allow gay marriage: Canada, Brazil, Argentina, Uruguay, Norway, Sweden, Denmark, Iceland, Netherlands, Belgium, France, Spain, Portugal, South Africa, and New Zealand.

Same-sex marriage is legal in some jurisdictions of Mexico and the United States. Currently, 12 states in the U.S. permit same-sex marriage, while 30 states have amended their constitutions to ban it.

Resource: Pew Research Center: A global snapshot of same-sex marriage