An Upper East Side Republican club was vandalized overnight — with a brick thrown through its window, two anarchy symbols scrawled on its front door and the locks glued, authorities said Friday.

The attack at the Metropolitan Republican Club on East 83rd Street near Lexington Avenue appeared to be at least partly tied to the scheduled appearance of right-wing provocateur Gavin McInnes at the club Friday night.

McInnes, a co-founder of Vice Media, heads a right-wing group called the Proud Boys, which has been characterized as a hate group by the Southern Poverty Law Center.

A note found at the club after the vandalism attack read in part, “The Metropolitan Republican Club chose to invite a hipster-fascist clown to dance for them, content to revel in their treachery against humanity.”

But the note also ripped the party in general.

“Tonight, we put the Republican Party on notice, in defiance to the policy of mass misery they have championed,” it read. “The US government has established concentration camps around the country for Latino people, shamelessly murders black people, and continues its war machine that has slaughtered Muslim people with impunity for decades.”

At a press conference in front of the club Friday afternoon, New York GOP leaders fumed about the vandalism.

“This is terrorism,” said state Senate candidate Pete Holmberg. “The people in this district are civil. These people came from outside.

“This is an outside threat, and they’ve been sort of validated by [Hillary] Clinton,” Holmberg added, three days after the Democratic former presidential candidate said her party needs to put “civility” on the back burner until it wrests control of Congress from the GOP.

Marc Molinaro, the GOP candidate for governor of New York, said in a statement, “This type of political violence and rank vandalism is unacceptable, and I call on New York Gov. Andrew Cuomo to condemn this attack immediately and call for calm on the political left.”

Cops discovered the vandalism while responding to a call of a burglary at the address at 1:50 a.m.