Chris Upton, headteacher at Tarleton Community Primary School, in Lancashire, said: "Saffie was simply a beautiful little girl in every aspect of the word.
"She was loved by everyone and her warmth and kindness will be remembered fondly. Saffie was quiet and unassuming with a creative flair."
Saffie Rose Roussos was at the concert with her mother Lisa Roussos and Saffie's sister, Ashlee Bromwich, aged in her 20s, from Leyland, Lancashire, who are both now in separate hospitals being treated for injuries, friends said.
The news comes after a desperate appeal was made to trace the whereabouts of Saffie.
Friends posted an appeal on Facebook in a desperate bid to trace her.
Kate Tinsley, whose daughter Jessica is best friends with Saffie at Tarleton Community Primary School near Preston in Lancashire, said earlier: "I've tried to contact Saffie's mum and none of the message have gone through on the phone.
"Jessica has gone to school today not knowing a thing. My daughter is best friends with her in school. Everybody is worried, the whole village. Everybody is in bits waiting for news, just some news that she's okay, she's alive."
Another family friend posted the Facebook appeal to help the desperate search for the missing school girl.
She said: "My friend Lisa and her daughters Ashlee and Saffie were at the concert last night. Saffie-Rose, 8 years old is still missing.
"Her mum Lisa and sister Ash are in hospital with shrapnel injuries which are not life threatening but Saffie is still missing."
Hundreds of people are desperately searching for loved ones in the aftermath of a terror attack at Manchester Arena which left 22 dead and at least 59 injured.
Parents, relatives and friends are frantically trying to contact people still missing after the explosion, flooding social media with images as they try to track them down.
Thousands of teenagers were inside the arena for a concert by Ariana Grande on Monday night, and Greater Manchester Police chief constable Ian Hopkins has confirmed children are among those killed.
Facebook has activated its safety check feature so people can let loved ones know they are safe, and an emergency helpline, 0161 856 9400, has been set up for those searching for loved ones.
Two hotels near the arena, the Holiday Inn and Premier Inn, both took in stranded children in the immediate aftermath and looked after them overnight.
Around 60 people caught up in the terror attack were reported to have been taken in by Holiday Inn hotels near the arena.
Holiday Inn was unable to confirm the number of people it was helping but said it had supported them throughout the night by offering "immediate refuge".
A spokeswoman said: "The hotel teams at Crowne Plaza Manchester City Centre and Holiday Inn Express Manchester City Centre - Arena have both been working closely with the emergency services throughout the night, supporting members of the public who needed immediate refuge.
"The hotels are fully operational and continue to offer support."