The Real Madrid star was picked behind only DeAndre Ayton (Phoenix Suns) and Marvin Bagley III (Sacramento Kings).
He is going to Dallas, which selected Trae Young with their number five pick but had agreed on a trade with Atlanta.
Dončić, who is only the fifth top 3 pick in NBA history to not come from the US, told a reporter immediately after being drafted that he had been in talks with Dallas and that he was glad and happy to just be in the NBA.
Asked how his play in the Spanish professional league will translate in the NBA, he said that he had played with a lot of ex-NBA players who had taught him so much about the NBA and that he thought that he was ready for the challenge.
Dončić later told the STA that he was not surprised that he ended up in Dallas: "I had been talking to Dallas much more. I really liked them ... and I'm very happy to be in Dallas."
The MVP of the past EuropeLeague season is looking forward to playing at the side of the legend of European and NBA basketball, Germany's Dirk Nowitzky.
"I'm extremely happy that I'll be able to learn from him," said Dončić, who will travel to Dallas today.