All About Cooper Flagg's Brothers (Including His Twin Who Also Plays Basketball)

Cooper Flagg has a close bond with his basketball-loving brothers.

The rising athlete — who is expected to be drafted first by the Dallas Mavericks in the 2025 NBA Draft on June 25 — and his siblings were raised by their parents, Kelly and Ralph Flagg, in Newport, Maine. The couple first welcomed son Hunter in August 2004. (Hunter had a twin brother named Ryder, who died two days after birth from complications.)

In 2006, Kelly became pregnant with another set of twins, and in December of that year, Cooper and his twin brother, Ace, joined the family. It wasn't long before the trio of brothers fell in love with basketball — the sport both of their parents played in college. Cooper credits both his family and his hometown with his love of the game.

“The place I grew up in taught me to work for everything, to value fundamentals, and to never back down just because someone thinks they come from a bigger program or place,” he told The Ringer in June 2025.

From growing up in Maine to their shared love of basketball, here's everything to know about Cooper Flagg's brothers.

Cooper comes from a family of twins

Ralph and Kelly married in the early 2000s and started their family shortly thereafter.

At 24 weeks pregnant with twins, Kelly went into premature labor on Aug. 4, 2004. The couple's son Ryder died two days later, and Hunter was in the neonatal intensive care unit for 109 days.

In 2006, after several cycles of IVF, Kelly became pregnant with twins for a second time. They welcomed Ace and Cooper on Dec. 21 of that year.

Cooper and his brothers grew up playing basketball

Growing up in Newport, the Flagg brothers spent most of their free time playing basketball — whether at the gym with Ralph or in their driveway at home.

"We couldn't play a game in our driveway without someone bleeding," Ace told New Center Maine in April 2025. "The game would end when someone ran in yelling for mom, but it was always fun."

In a 2022 interview with The Portland Press Herald, Cooper described himself as the "best trash talker" in the "old driveway basketball league."

"I’d talk smack, and then they'd end up punting the ball across the street," he said.

Kelly added, "Hunter [would get] the most frustrated. He would lose his mind."

Ace is committed to the University of Maine, where Hunter attends school

Cooper's brothers have also seen some basketball success over the years.

In 2022, Cooper, Hunter and Ace played on the same team at Nokomis Regional High School in Maine, and the trio led the squad to a state championship.

Two years later, Ace helped his team at Montverde Academy in Florida secure a state championship, and most recently, he led Greensboro Day School in North Carolina to a state title in February 2025.

"I'm proud of him," Cooper said during a press conference shortly after Greensboro's big win. "[Ace] got three state championships in three different states through his high school career, so that's pretty cool."

Ace will continue his basketball career at the University of Maine — where Hunter is currently working toward a degree in sports management, per his LinkedIn.

The University of Maine is also where Kelly played basketball in the late '90s.

Ace is dating a basketball player

The family's passion for basketball extends to their love lives, too. Ace has been dating Lizzy Gruber — who is committed to the University of Maine's women's basketball team — since October 2022, per Instagram.

The couple celebrated their second anniversary in October 2024, which Ace marked with a sweet post on Instagram.

"730 days with her❤️," he captioned the photo.

Cooper's brothers are supportive of his basketball career

Hunter and Ace are Cooper's biggest fans — on and off the court. The entire Flagg family is expected to join Cooper — who is anticipated to be the first overall pick — at the 2025 NBA Draft on June 25 in New York City.

"I know my mom is going to be bawling her eyes out when my name gets called. My oldest brother will probably cry too," Cooper told Today that month.

While speaking to ESPN's Malika Andrews on June 24, the basketball star said he's "really excited" to experience draft day with his family by his side.

"It's going to be incredible. This is the moment I've dreamed about my entire life," he added. "To be able to go through it with them and have them along for this experience is truly surreal."