Can a Same-Sex Couple Both Be Legal Parents in Ontario Without Adopting?

In many cases, yes. If you and your spouse have a child through donor insemination or assisted reproduction, the birth parent's spouse is a legal parent without adoption. Parentage for a child who is not adopted is set under the Children's Law Reform Act, not the adoption rules.

That rule has limits. The spouse is not a parent if they did not consent before conception or withdrew their consent, and the rule does not apply to surrogacy or posthumous conception. A sperm donor who agreed in writing before conception not to be a parent is not a parent. Up to four people, including the intended birth parent, can sign a written pre-conception parentage agreement and are recognized as parents when the child is born.

With surrogacy, the written agreement must be made before conception, and the surrogate and intended parents must each receive independent legal advice. The intended parents become parents once the surrogate gives written relinquishment, which cannot happen until the child is seven days old. If those steps were missed, a court declaration of parentage may be an option, so ask a lawyer which route fits.