Downtown chicken and champagne joint Birds & Bubbles is suing its landlord because an upstairs tenant’s feeder attracted birds that bombed the eatery’s outdoor seating, forcing it to close.

The basement eatery at 100 Forsyth St. was going strong until last summer, it says in a $1.5 million Manhattan Supreme Court suit.

“We also had bird seed everywhere, constantly, every day,” chef and owner Sarah Simmons told The Post.

The landlord did not ­respond to messages.