Flagg, 206cm forward from Duke University is expected to play major minutes for the Mavericks, who traded Luka Doncic to the LA Lakers a year after Doncic took them to the NBA Finals.
Watch live coverage of the 2025 NBA Draft with ESPN on Kayo Sports | New to Kayo? Get your first month for just $1. Limited time offer.
Flagg will play alongside the likes of Anthony Davis and centre Daniel Gafford, who was re-signed by the Mavericks this week.
The 18-year-old lands in the already stacked Western Conference and without Irving and Doncic, the Mavericks may be up against it to make the playoffs in Flagg鈥檚 rookie year.
Flagg joins Elton Brand, Kyrie Irving, Zion Williamson and Paolo Banchero as Duke players to be taken No. 1 in the NBA Draft.
The San Antonio Spurs took Dylan Harper with the second pick, and Philadelphia selected VJ Edgecombe with the third pick.
Draftee slammed for cocky act
The rest of the top 10 of the draft is unclear, with Ace Bailey and Dylan Harper highly rated, but Bailey has refused to work out with NBA teams, a cardinal sin in the draft process.
Bailey, a sharpshooter from Rutgers in New Jersey, has been criticised by Philadelphia鈥檚 Paul George, who said: 鈥淚f I鈥檓 Ace Bailey I can鈥檛 get mad if my stock drops.
鈥淗e鈥檚 cancelled all workouts. He hasn鈥檛 worked out for any team. You鈥檙e not in a position to be making those demands. Make it to the league first.
鈥淭hat鈥檚 a kid that鈥檚 been paid in college, 鈥業 got money, I don鈥檛 care. I鈥檓 gonna tell you where I鈥檓 gonna go鈥.
鈥淚t鈥檚 almost the 鈥榤e before the team鈥, before he鈥檚 on the team.鈥
Which Australians are in the NBA Draft?
This year, there are four Australians expected to be picked in the second round of the NBA Draft 鈥 Sydney Kings youngster Alex Toohey, 220cm Brisbane Bullets giant Rocco Zikarsky, Duke point guard Tyrese Proctor and Illawarra Hawks NBL champion Lachlan Olbrich.
Proctor is the most highly rated prospect of the Australians after he spent three years playing college basketball at Duke. The 21-year-old is expected to be picked early in the second round.
Another top Aussie prospect is Alex Condon, a 20-year-old centre who achieved NCAA glory with the Florida Gators this year, becoming the sixth Australian to win the US national college basketball championship.
Condon had been slated to be picked late in the first round, possibly to the Brooklyn Nets, but last month he made the decision to withdraw from this year鈥檚 NBA Draft to return to Florida for another year of college hoops.
It鈥檚 becoming increasingly common for players who aren鈥檛 expected to be first round picks to pull out of the NBA Draft to stay in college, especially after name, image and licence (NIL) rules were changed in 2021.
NBA Draft full order of picks
1. Dallas Mavericks – Cooper Flagg, SF/PF, Duke
2. San Antonio Spurs – G, Dylan Harper, Rutgers University
3. Philadelphia 76ers – VJ Edgecombe, Baylor
4. Charlotte Hornets
5. Utah Jazz
6. Washington Wizards
7. New Orleans Pelicans
8. Brooklyn Nets
9. Toronto Raptors
10. Phoenix Suns (via Houston)
11. Portland Trail Blazers
12. Chicago Bulls
13. Atlanta Hawks (via Sacramento)
14. San Antonio Spurs
15. Oklahoma City Thunder (via Miami)
16. Orlando Magic
17. Minnesota Timberwolves (via Detroit)
18. Washington Wizards (via Memphis)
19. Brooklyn Nets (via Milwaukee)
20. Miami Heat (via Golden State)
21. Utah Jazz (via Minnesota)
22. Brooklyn Nets (via Atlanta)
23. New Orleans Pelicans (via Indiana)
24. Oklahoma City Thunder (via Los Angeles Clippers)
25. Orlando Magic (via Denver)
26. Brooklyn Nets (via New York)
27. Brooklyn Nets (via Houston)
28. Boston Celtics
29. Phoenix Suns (via Cleveland)
30. Los Angeles Clippers (via Oklahoma City)