The five-minute, student-produced video highlighted the school's volunteer and community service programs.
The Chicago Sun-Times reports that the singer told students she admired their passion and volunteerism. Rihanna showed up more than five hours late, but some in the crowd said she was worth the wait.
She also posed for photos before heading off to her Friday night concert at Chicago's United Center. Barrington freshman Nisha Ali says "the fact that she came here and thanked us was a huge deal."
"I'm late for everything so I totally understand," said Allison Burman.
But Rihanna's timing Friday afternoon at Barrington High School turned some students off.
"I think it's very rude of her to do this," said Barrington High School junior Megan Defeo. "We worked really hard on our video and to win this contest, and so for her not to show up after all of this is really rude and disrespectful of her."
In a tweet, Rihanna blamed traffic, saying "the Chicago traffic is not working." Once there, she recognized the students' service.
"I think you guys coming together as one, not just for your school but for your communities. You reached out to other people," she said.
"Finally she came and it was brief but very nice and worthwhile, definitely worth the wait," said student Nicole Zero.
Friday night, some Barrington students were at the concert with no hard feelings at all whatsoever.
"I can't even believe that we're so lucky," said student Athenamarie Demeros. "For her to come to Barrington and then for us to be here and see her again, it's amazing."
The students received VIP passes, as well as autographed posters.
The Associated Press contributed to this report.