A Long Island teacher is fighting racial injustice — one page at a time.

Tara Drouin, 47, wrote a heartfelt book and accompanying song about diversity that she’s shared with elementary school students around New York — a lesson she told The Post is now more critical than ever as the country reels over the death of George Floyd.

“I’ve experienced so much sadness watching rioting and seeing what happened to Mr. Floyd — this issue of racism in our country has to be stopped,” said Drouin, of Bethpage.

“With youth, I feel like that’s where we’re going to make a change,” added the 47-year-old mom, whose 9-year-old daughter is mixed race.

Drouin — who was furloughed in March from her job teaching 3-and-4 year-olds at Colors and Kids Montessori school in Little Neck amid the coronavirus pandemic — was inspired to write the tune, “One Heart” in 2016 after seeing the diverse faces in her classrooms, she said.

She then turned the song into a book of the same name, which was published in 2018 and features colorful images of children of all races playing together outside.

“We may not all look the same/ our skin might be a different shade/ but inside everybody’s got one heart!” the book and song both the book and song say.

The goal, she said, is to spread the message that “we are all one race — the human race.”

Drouin, a musician who performs in the local band iRideSense, said she was also inspired to spread the message of “acceptance kindness and unity and love” because of her daughter, Kaya.

“Racism is taught. But if at a young age you learn our differences are what make us unique, that can help,” she said. “It’s a healing potion — and a way to bring people together.”