Social-media users, beware — that next Facebook “poke” could be from a process server.

In a groundbreaking court ruling, a Staten Island man got permission to use Facebook to serve his ex-wife legal notice that he doesn’t want to pay any more child support.

A Family Court official ruled that Noel Biscocho could use Facebook to serve Anna Maria Antigua because other, more traditional methods to slap her with papers have not worked.

Staten Island Support Magistrate Gregory Gliedman noted in his Sept. 12 order that it was the first of its kind in New York, and also the first in the United States that didn’t involve an attempt to serve someone overseas.

Seeking to cancel his court-ordered $440-a-month child support based on their son having turned 21, Biscocho, in a July 6 affidavit, said he tried to reach his ex at her home, but was told that Antigua had moved out with no forwarding address.

A Google search also proved fruitless, and neither his son nor the couple’s daughter, 22, returned messages.

But Biscocho noted that Antigua “maintains an active social media account with Facebook” — and had even “liked” some photos posted on Facebook by Biscocho’s second wife “as recently as July.”

Gliedman ruled it was “impracticable” for Biscocho to serve Antigua personally, through someone at her home or business, or by taping a copy to her door and mailing her another.

“However, despite the absence of a physical address, [Biscocho] does have a means by which he can contact [Antigua] . . . namely the existence of a social media account,” he wrote.

Lawyer Michael Stutman, head of family law at Mishcon de Reya in Manhattan, hailed Gliedman’s ruling, saying: “The idea that physically handing someone a piece of paper is the only way to serve notice is archaic.”