A well-connected New York City firefighter who was once booted from the FDNY over racist online rants allegedly defecated in a stranger’s backyard during a drunken night in New Jersey, authorities said.

Joseph Cassano, the son of former fire commissioner Sal Cassano, allegedly pooped on the lawn furniture and the sidewalk of the Lake Como residence before stumbling into the garage, where he passed out.

Police arrested the probationary firefighter on Sunday and issued him a summons for criminal trespass and criminal mischief.

The New York Fire Department was not immediately available to comment.

Cassano resigned from his job as a city EMT in 2013 after the Post exposed his antisemitic Twitter account.

“I like jews about as much as hitler. #too far? nope!,” he wrote in one missive.

But that didn’t stop the FDNY from admitting him into the academy, which he graduated from in April.