A Long Island school district has been referred to the Department of Justice for allegedly violating federal civil rights law with a controversial name change of its Thunderbirds mascot in response to a state ban on Native American imagery.

The Connetquot Central School District was slapped with a letter Friday after a federal review conducted by the Office for Civil Rights found the district flouted Title VI of the Civil Rights Act of 1964, when ditching its Thunderbirds nickname for the “T-Birds.“

“After the District changed its Native American mascot in response to a state regulation that OCR has determined to be discriminatory, Connetquot has not yet taken the steps necessary to come into compliance with federal civil rights law,” Assistant Secretary for Civil Rights Kimberly Richey said.

“It is neither fair nor lawful to permit certain national-origin-based names and mascots while erasing others, and we are now referring the matter to the Department of Justice for further enforcement.

“The Trump Administration remains committed to upholding equal treatment under the law,” she concluded.

The name change was made last year to comply with a 2023 New York state law banning Native American-inspired names, mascots and imagery. After a legal battle, Connetquot officials reached a compromise with state leaders in September to shorten the nickname to T-Birds.

But federal officials argued the rebranding discriminates on the basis of national origin and race, saying the ban doesn’t apply the same standard to other racial and ethnic groups.

“Based on a review of publicly available information … OCR determined that the District is not in compliance with Title VI and its implementing regulation,” the letter sent to the Suffolk County school district said.

“The Department therefore requests and recommends that the DOJ commence judicial proceedings against the District for violating Title VI.”

The Connetquot Central School District did not immediately respond to The Post’s request for comment.