Young also had 11 assists.
His long 3-pointer with 1:15 remaining gave the Hawks a 125-123 lead.
"Those two buckets effectively won the game," said 76ers coach Brett Brown, who said Young "was unique tonight."
Young has five games with at least 30 points and 10 assists. According to research provided by the Hawks, Young is tied with Stephen Curry and Michael Jordan for the second-highest total of those games among rookies. Only Oscar Robertson, with 24 games with at least 30 points and 10 assists, had more as a rookie.
“He is rookie of the year,” Hawks coach Lloyd Pierce said. “... We rely on him a lot and he delivers a lot. I don’t know if anyone has played better basketball in their rookie season than he is or anyone else over the last couple of years. The stuff he is doing - facilitating, he has played in every single game and he has performed. He has been our go-to guy down the stretch. I just think there is a lot to be said about our growth as a team and how we’ve progressed and teams we’ve beat and how we’ve played as the season has gone on and he’s been a major part of that.”
After Young’s game-winner, Donovan Mitchell of the Jazz posted on social media: “ROY @TraeYoung.” The post was seconded by the Kyle Kuzma of the Lakers and Blake Griffin of the Pistons.
Atlanta has won two of three from the 76ers, including a split of two games at Philadelphia. Butler said the 76ers still came in too confident, thanks to the winning streak.
"I think it's the fact that we think that we're a good team so we can just come in and do whatever we're going to do and think that we're still gonna win," Butler said. "... I'm telling you, I think that's what it was."
Butler missed a long attempt after the final buzzer sounded.
Taurean Prince had 23 points for the Hawks.
Joel Embiid had 27 points and 12 rebounds, and Butler had 25 points for Philadelphia.
After snapping Utah's five-game winning streak by beating the Jazz 117-114 on Thursday night, the Hawks dropped another streaking playoff-bound team.
Butler, who tied the game with a layup, sank two free throws to give Philadelphia a 127-125 lead. Prince answered with a tying layup.
The Hawks were left with 3.5 seconds after the 76ers' 24-second violation, with Butler's miss waved off as coming too late.
The Hawks’ John Collins had a short description of the decisive play. "Give the ball to Trae, and he takes off," Collins said.
The Hawks matched their season high for most points in a first half. The Hawks also scored 74 points in the first half against Miami in a 123-118 win on Nov. 3. The 74 points were the most allowed in a first half by the 76ers this season.
The Hawks (26-48) play at the New Orleans Pelicans Tuesday at 8 p.m.