Arturas Karnisovas, the Bulls' executive vice president of basketball operations, aggressively pursued Donovan after the coach left the Oklahoma City Thunder, sources said, selling Donovan on a partnership and vision for a talented young roster and a chance to lead one of the league's anchor franchises.
In an official statement, Donovan thanked the team's ownership "for the opportunity to coach the Chicago Bulls" and said he is looking forward to working with Karnisovas.
"I'm excited to partner with Arturas as we work together on behalf of this historic franchise," he said.
Donovan's representative, Oliver Winterbone of Wasserman Media Group, finalized the deal with Chicago officials on Tuesday, sources said.
Karnisovas and general manager Marc Eversley believed Donovan was the best coach available and that his track record in Oklahoma City -- including five straight trips to the playoffs in the Western Conference -- made him a good fit for the Bulls.
"We are very pleased to welcome Billy and his family to the Chicago Bulls," Karnisovas said. "The success that he has sustained over the course of his coaching career puts him on a different level. We feel his ability to help his players reach their potential, both individually and collectively, will mesh well with our roster. Whether as a player or as a coach, he has won everywhere his career has taken him, and we hope that will continue here in Chicago."
Donovan, 55, was the National Basketball Coaches Association's co-Coach of the Year with the Milwaukee Bucks' Mike Budenholzer for 2019-20. The NBA's coaches vote on the award.
Karnisovas dismissed former coach Jim Boylen in May and talked with a number of candidates before extending the offer to Donovan.
In his first season with Oklahoma City, Donovan advanced to the West finals with Kevin Durant and Russell Westbrook, and he reached the playoffs in each of the next four campaigns. Donovan was 243-157 (.608) as the OKC coach. He signed a five-year deal with the Thunder upon arriving from the University of Florida, where he won two national championships.
The Bulls are counting on Donovan to give them a lift after the team missed the postseason for the fourth time in five years.
On the court, the Bulls are led by Zach LaVine, who averaged 25.5 points this season, and Lauri Markkanen, who took a step back. The 7-footer from Finland missed 15 games with a pelvic injury, and his scoring and rebounding numbers dropped.
Information from The Associated Press was used in this report.