In return, the Hawks acquired the draft rights to Trae Young, who was selected by the Mavs at No. 5 overall.
"I've been talking to a lot of teams, but especially Dallas, they've been talking to me, they were so nice to me, and I'm glad you know ... I'm just happy to be in the NBA. I'm just happy to be a part of that," Doncic told ESPN after learning he would be sent to Dallas.
Dallas also sent a protected 2019 first-round pick to Atlanta. The pick is top-five protected the next two years, top-three protected in 2021 and '22 and unprotected the following year, according to Mavs president of basketball operations Donnie Nelson.
The move has minor cap ramifications for Dallas. The cap hit for Doncic will be $6.6 million and not $5.4 million had the Mavericks stayed at 5. Dallas still is positioned to be aggressive in free agency, with coach Rick Carlisle acknowledging that center will be the franchise's priority in this summer's market, when DeMarcus Cousins and DeAndre Jordan will be among the unrestricted free agents.
Earlier discussions between the Mavs and Hawks included Dallas sending Wesley Matthews Jr. to Atlanta and receiving Kent Bazemore. That would have been a cost-cutting move for the Hawks with Matthews due to make $18.6 million this season in the final year of his contract and Bazemore owed $37.4 million over the next two seasons.
Dallas balked at taking back Bazemore's contract and giving up a future first-round pick, so the veterans were eliminated from the discussions. The deal was agreed upon when the Suns were on the clock with the first overall pick.
"I have a lot of ex-NBA players on my team, I play against a lot of ex-NBA players," Doncic said. "I have some great teammates, they taught me so much, and especially the NBA players. They've been talking to me about the NBA the whole year. They know I was coming, so I think I was prepared."
Longtime Mavs great Dirk Nowitzki immediately welcomed Doncic aboard.
Welcome my man @luka7doncic— Dirk Nowitzki (@swish41) June 22, 2018
The Mavs had the third-best lottery odds after their 24-58 campaign but fell to the fifth pick, requiring a trade to move up for Doncic, their prime target.
"Future draft picks to me are of very little interest at this point," Carlisle said. "We've got to take this group and move these guys forward."
Many consider Doncic the most NBA-ready player in this year's draft class.
The Slovenia-born point guard is the reigning MVP of the Euroleague regular season, Euroleague Final Four and ACB regular season. Nicknamed "Wonder Boy," he became the youngest player to debut for the Real Madrid first team in the ACB at 16 years, 2 months and 2 days. At the time, he became the third-youngest player to debut in the ACB overall, trailing 14-year-old Ricky Rubio and 15-year-old Ángel Rebolo.
This past season for Real Madrid, the 6-foot-8 Doncic averaged 14.7 points, 5.1 rebounds and 4.6 assists. He hit a bit of a wall after playing 18 straight months without a break for Real Madrid and the Slovenian national team, souring some scouts with a handful of underwhelming performances in March and April. But he still found a way to help Real Madrid win the EuroLeague Final Four and was awarded MVP honors for his effort before notching the championship series victory in the ACB.
"We've got to understand that he is 19," said Carlisle, who mentioned that Doncic likely will not play the entire summer league schedule coming off a long Euroleague season. "NBA stardom doesn't happen overnight. It's going to be a process, and we've got to protect him as well as be excited for him to get on the floor and do the things that he's done so well in Europe."
As for Young, Hawks personnel had long been enamored with the Oklahoma sharpshooter.
"I knew they were very interested," he told ESPN. "I had a really good workout when I went out to Atlanta. I had a great time visiting with the organization and the front office, and I loved spending time with Coach [Lloyd] Pierce and can't wait to get out there, meet the fans and get ready to spend some time with my new teammates."
Young became the first player in Division I history to lead the nation in both points (27.4) and assists (8.7) since assists became an official stat in the 1983-84 season. The freshman guard also finished atop the Oklahoma and Big 12 lists for highest scoring average in a season.
Young had three 40-point games this season, including a Sooner-record 48 on the road against rival Oklahoma State. His scoring, vision, 3-point shooting (36.0 percent) and small stature (6-foot-2, 176 pounds) have earned comparisons to Stephen Curry.
Young ended up two spots behind Curry on the list of top scoring seasons in Division I over the past 10 years. He placed fifth on the list with his 27.4 points per game this past season, and Curry is third with 28.6 in his last season at Davidson.
Hawks general manager Travis Schlenk said he was won over by Young's floor leadership.
"We love his ability to pass the ball, to make other players better with his court vision,'' said Schlenk, a former assistant GM with the Warriors. "Obviously he gets a lot of notoriety for his long-range shooting, but I think his ability to pass the ball is what we really liked about him.''
Information from ESPN's Adrian Wojnarowski and Bobby Marks and the Associated Press was used in this report.