The City Council on Wednesday approved legislation that will allow New Yorkers to select a third gender category on their birth certificates.

The change, which has the backing of Mayor de Blasio, ensures a new “non-binary” identity category known as “X” will be available on birth certificates for those who don’t consider their gender to be male or female.

It was approved 41-6 in a Council vote.

Council Speaker Corey Johnson, who introduced the legislation, said it will make “New York birth certificates more inclusive for all and will send a powerful signal to the world that New York City government works for everyone.”

But Councilman Robert Holden (D-Queens), who voted against the bill, told The Post afterwards that he’s concerned it will open the door to “abuse” and other “public safety issues.”

“Just having anyone – without going through a doctor – say they’re another gender or X; that could lead to abuse and all sorts of problems,” he said. “We need more oversight.”

“How does ‘X’ describe a person? Don’t we have to have some standards and order?” he asked.

Under the bill, transgender New Yorkers will no longer need a letter from a physician or an affidavit by a licensed health care provider to change their gender on the government form. Instead, those born in the Big Apple will be able to submit their own affidavit requesting a gender-identity change.