A tony waterfront Long Island village that couldn’t find anyone to run for mayor just elected an ex-pol who wasn’t even on the ballot.

Paul Rupp, 66, won election as Bayshore’s mayor June 16 after receiving 519 votes in a bizarre write-in campaign — despite not running for office and even endorsing another guy just days before the wild situation.

Rupp — who previously served as Bayville’s mayor from 2014-18 and as a village trustee for eight years before that — posted on Facebook two days earlier that he had been approached by multiple residents asking if he would accept the position as mayor if written in.

The ex-pol graciously said he would do the job if asked — after no one filed paperwork to run for the office.

“I would be honored to serve our Village once again,” he wrote in the post — just after endorsing former village trustee and Deputy Mayor Joe Russo.

Roughly 1,400 voters cast a ballot for mayor in the village of 7,000, with 46 different names being written in by various residents.

The village’s current mayor, Steve Minicozzi, came in second place and received 382 votes despite stating he was not running for re-election and did not want the job.

After Rupp’s post on Facebook saying he would accept the post if pushed, residents began to rally behind him.

In his post, Rupp listed affordability, transparency and infrastructure as his biggest priorities when he takes office.

Rupp has previously described himself as a fiscal conservative who aims to avoid raising taxes and left office with a budget surplus in 2018.

“My objective is to keep the Village safe, secure and fiscally sound,” Rupp said in accepting the $5,000-a-year gig.

Voters also re-elected incumbents Anne Walsh and Aimee DiBartolomeo to their trustee seats.