General manager Dell Demps, who'll lead the search for a new coach, said he informed Davis of the decision in a one-on-one meeting after the move was made. When asked about Davis' reaction, Demps said, "That'll stay between us."
Davis, already a two-time All-Star at age 22, is entering the final year of his contract before he becomes a restricted free agent. He can sign an extension as early as July, but also could choose to wait until next offseason.
Basketball fans in New Orleans have seen one superstar -- guard Chris Paul -- become alienated by the handling of a coaching change. That was the firing of Byron Scott early in the 2009-10 season, when the team was under different ownership and management.
Paul wound up being traded to the Los Angeles Clippers before the 2011-12 season after making it clear he would not sign an extension with New Orleans.
Time will tell if Davis reacts similarly over the departure of Williams, who also has coached the Pelicans' power forward as an assistant on Team USA.
A day after the Pelicans were eliminated from the first round of the playoffs by top-seeded Golden State, Davis called Williams "a great coach," adding, "The whole team loves him."
Demps said Davis' relationship with Williams was considered by ownership and management, "and obviously we still made the decision."
The change came only weeks after owner Tom Benson congratulated Williams and the entire basketball operations staff for "a job well done" following a season in which New Orleans qualified for its first playoff berth since 2011.
"Monty did a great job. He's done some really good things for us, but going forward we just felt like we needed something different to get to the next level," Pelicans executive vice president Mickey Loomis said.
Williams has an overall record of 173-221, with two playoff appearances since landing his first heading coaching job with the Pelicans in 2010.
His first postseason appearance -- a first-round loss to the Los Angeles Lakers -- came with Paul on the roster.
Williams then shepherded the franchise through a rebuilding period that included a prolonged period of uncertainty during which the NBA temporarily purchased the club from founder George Shinn in December 2010 before selling in April 2012 to Benson, who also owns the NFL's Saints.
In a written statement provided to The Associated Press, Williams thanked Pelicans ownership and management for a "unique opportunity."
"My focus today is to appreciate the great journey over the last few years," Williams said. "I need to thank my coaches and players because we take pride in our accomplishments as a group in progressing in the right direction and making the playoffs through the challenges of a long season."
Loomis and Demps declined to cite a single problem they had Williams. Rather, they stressed that he did a number of things well while coaching a young, injury-riddled team, and that firing him was difficult on personal and professional levels.
Loomis also said Williams appeared surprised by the decision.
So was Golden State's Steve Kerr.
"You've got to be kidding me," Kerr said when told about Williams' firing.
"You never know what's going on being the scenes, but I know from facing New Orleans in the first round, I thought Monty was terrific," Kerr added. "He had his team well prepared."
While Williams was hired before Demps by previous ownership and the two acted as peers, Loomis, who is also general manager of the Saints, said he prefers a clear hierarchy in which the coach answers to the general manager, who in turn answers to ownership. In the Pelicans' case, Loomis advises Benson on major decisions but does not take an active role in basketball operations, readily acknowledging that his background is in football.
Loomis and Demps declined to outline specific qualities, accomplishments or experience they want the next coach to have. Demps only said that he hopes many top coaches will be interested in the chance to coach a talented young roster led by a budding superstar in Davis.
Because Davis is due to be a restricted free agent after next season, he'll likely have to agree to at least a three-year extension, but could opt for a maximum five-year extension if he's happy with the direction of the club.