One of the people, speaking on condition of anonymity because the agreement had not been announced, told The Associated Press on Wednesday night that Williams agreed to a six-year contract.
Phoenix fired Williams two-plus weeks ago, two years after reaching the NBA Finals and a year after he won the league’s coach of the year honors.
The 51-year-old Williams won 63% of his games over four regular seasons with the Suns, but Phoenix was eliminated in the Western Conference semifinals two years in a row after losing to Milwaukee in the 2021 NBA Finals.
The Pistons would be thrilled to approach that level of success anytime soon under Williams.
Detroit won an NBA-low 17 games last season, losing 30% or fewer games for the fourth straight season under Dwane Casey, who stepped down as coach with one year left on his contract to take a role in the front office.
The Pistons did not have good fortune in the draft lottery, landing the No. 5 pick overall for the second straight year and missing out on an opportunity to draft Victor Wembanyama.
Detroit, a three-time NBA championship franchise, has earned a spot in the playoffs just twice in 14 years.
Jaden Ivey and Jalen Duren, the No. 5 and No. 13 pick overall last summer, did provide hope for the future with their play last season. Cade Cunningam, the No. 1 pick overall in 2021, had his second season stunted by shin surgery after playing in just 12 games.
Bojan Bogdanovic, who averaged a career-high 21.6 points, Isaiah Stewart, James Wiseman and Marvin Bagley are expected to be back.
The young team, with some experienced players in the rotation, will have a proven leader on the bench.
Williams is 367-336 in nine seasons as an NBA head coach with a 29-27 postseason record. He had a five-year stint with the New Orleans Pelicans, who fired him in 2015 with a 173-221 record and two playoff appearances.
AP Basketball Writer Tim Reynolds contributed to this report.
Larry Lage, The Associated Press