The Indianapolis Colts dancer, known as Leanna E, met the 17-year-old and hugged him as he apologised.
She tweeted a smiling photo of herself with the embarrassed student.
The unidentified boy had jokingly griped in a Snapchat photo that his friend put him next to a black woman, though he used the n-word.
"A week ago I was the victim of a racial slur that was shared around the world," Leanna tweeted.
"Today, I chose forgiveness & feel stronger because of it."
The controversy began on 14 December when Leanna and another cheerleader posed for a picture with two students from Western High School in Russiaville, a town 60 miles (96km) north of Indianapolis, during an event to promote a blood donation campaign.
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The teenager later posted an image to Snapchat with the caption: "Of course [other student's name] put me next to the [racial slur]."
The photo caused outrage and went viral on social media.
Leanna contacted the school principal, not to demand that the boy be punished, but to express concern for his welfare after hearing that he had received physical threats amid all the backlash.
"I just was concerned for how he was handling it, and [Principal Rick Davis] said he [the boy] wasn't handling it well," she said.
"That broke my heart to know that."
The headmaster arranged for the two to meet.
Leanna went to shake the boy's hand when they met an Indianapolis Colts conference room on Wednesday night, but he instead greeted her with a hug and flowers.
"He actually referred to himself as a dumb kid that messed up and he said he was trying to be funny and wasn't and that he made a mistake and he was sorry," she told the IndyStar, "very sorry for hurting me and others."
The boy's mother, who accompanied him to the meeting, thanked the cheerleader for her forgiveness and told her the boy had not learned such language at home, Leanna said.
The cheerleader told the IndyStar: "I'm at peace with it."
"I hope that people look at themselves and step back and realise everybody makes mistakes," she added. "Nobody's perfect."
A US black cheerleader who was targeted by a high school student's racial slur after she posed for a viral photo with him has forgiven the teenager.