On the three-week anniversary of Jeff Hornacek’s firing, the Knicks have agreed to terms in principle with a new coach — David Fizdale, an NBA source confirmed.

The deal reportedly is for four years, according to ESPN. The Knicks will make an official announcement next week when they will hold a press conference.

The 43-year-old former Grizzlies coach beat out Mike Budenholzer and David Blatt as Knicks brass pared its 11-man list down to three finalists in recent days. Mark Jackson’s candidacy had fallen by the wayside with concerns he hadn’t been in the NBA the past four years and it was unclear how he would assemble his coaching staff.

Fizdale, who becomes the team’s 11th head coach since Jeff Van Gundy resigned in 2001, doesn’t have the head-coaching experience of any of the other finalists but checked a lot of the other boxes on the wish list of Knicks president Steve Mills and general manager Scott Perry.

The feeling within the Knicks organization was Fizdale’s Memphis stint was upended prematurely by a feud with Marc Gasol in November. Mills and Perry looked at his conflict with the Spanish center as an aberration.

Fizdale was a longtime assistant with the Heat and got along famously with LeBron James, Dwyane Wade and Chris Bosh.

The Knicks’ first-year management team said it was vital the new coach had a connectivity with the players, something they believed Hornacek lacked. Also, working with the front office, which wants to be an extension of the coaching staff, was deemed key.

Sources in Memphis said Fizdale had no issues regarding communication with the Grizzlies management. Embracing analytics does not appear to be an issue either.

“You can throw him into any room, and he will be able to work with that room,’’ Heat coach Erik Spoelstra recently told the Palm Beach Post. “Anywhere. From where he grew up in South Central [Los Angeles], to a board meeting to a basketball camp, he can bring any group of people together. And I know I’ll always get the truth out of Fiz, even if it’s not what I want to hear.”

Budenholzer, the Knicks’ second choice, is expected to be the Bucks’ top candidate and is planning to interview with them. Milwaukee may be a better fit for Budenholzer as the Bucks are a playoff team on the rise with a healthy superstar in Giannis Antetokounmpo.

Also expected to interview for the Bucks’ job is Blatt, the former Cavaliers coach who took his team to the NBA Finals but also warred with James.

If James ever looks New York’s way, they will have a recruiting gem in Fizdale. However, besides not having the necessary cap space this summer, the Knicks could spend much of next season without injured star Kristaps Porzingis.

Fizdale also interviewed with Phoenix, Charlotte, Orlando and Atlanta. He will not be able to bring along his top Memphis assistant, J.B. Bickerstaff, who replaced him on an interim basis and was named Grizzlies’ head coach Wednesday. Bickerstaff thanked several people at his press conference, including Fizdale.

Fizdale could hire ex-Knicks coach Mike Woodson as his top assistant. Woodson told The Post he would listen to an offer should the Knicks hired Fizdale, even though Woodson is currently Doc Rivers’ assistant with the Clippers. Fizdale was an assistant coach under Woodson in Atlanta from 2004-08.

It’s unclear whether Fizdale will bring any of his Memphis assistants — Keith Smart, Bob Bender, Nick Van Exel, Greg Buckner and Adam Mazarei — as they may stay with the Grizzlies. Miami assistant Juwan Howard, who interviewed with the Knicks for the head-coaching job, could also be asked to join Fizdale’s staff.

Fizdale was with Miami for the team’s entire run with James, Wade and Bosh that ended with titles in 2012 and 2013.

On his visit to the Garden in April, Wade called Fizdale “a phenomenal coach” who “has defensive principles from Pat Riley.” Wade tweeted Thursday: “When one [door] closes. Another one opens. The future of New York just got a lot brighter (literally). [Congrats] my friend Coach Fizdale!”

“They got the best coach on the market, in my opinion,’’ echoed ESPN’s Chauncey Billups.

In 2016, Fizdale finally became a head coach with the Grizzlies, posting a 43-39 record before a rough-and-tumble, six-game, first-round playoff ouster by the Spurs.

But after an eight-game losing streak in November and a feud with Gasol, Fizdale was a goner. The Knicks believe Fizdale’s strength is his connectivity with players. His relationship with their young European players, Porzingis and Frank Ntilikina, will bear watching.