One of the city’s oldest male strongholds is finally allowing women to join.

Members of the 235-year-old Society of the Friendly Sons of St. Patrick, an organization that once included George Washington, voted “two-to-one” in favor of a motion to change their bylaws last week, its new president John Coleman told The Post.

The vote, which came after a hour-long “thoughtful, vigorous and respectful” discussion at the Princeton Club Monday night, saw 302 members in favor of female members, while 150 stood their ground on the prohibition.

“It was a packed room,” Coleman told The Post. “It was the largest crowd we’ve ever had at a quarterly meeting.”

Coleman said the charity, which supports educational initiatives and hands out scholarships, will present its “inaugural class” of women members at their annual fundraising dinner in March.