Adrian Wojnarowski of ESPN first reported the news.
Fisher played 18 NBA seasons with five teams and most notably started for the Los Angeles Lakers during their NBA championship stretch from 1999-2000 to 2001-02.
Fisher retired in 2014 and was hired as the New York Knicks head coach. The Knicks fired him midway through the 2015-16 season after he amassed a 40-96 record.
Since then, he's worked as a television broadcaster on TNT for national NBA broadcasts and Spectrum SportsNet for Lakers games.
Fisher replaces Brian Agler, who resigned in November after four seasons of leading the Sparks. During Agler's tenure, the Sparks made the playoffs four straight years and the WNBA Finals twice, winning in 2016.
Fisher has some work to do to get the Sparks back to their glory days. The Sparks regressed in 2018, as they finished 19-15 and were knocked out in the second round of the playoffs.
Los Angeles has a solid core with Candace Parker, Nneka Ogwumike and Chelsea Gray leading the way. Parker has one of the more decorated resumes in basketball today.
However, the days of a few teams dominating the WNBA landscape season after season (a la the Sparks and Minnesota Lynx in years past) appear to be over. There's now more parity in the top half of the conference.
While the Seattle Storm led the league with a 26-8 record en route to a Finals win, the Phoenix Mercury nearly beat them in the semifinals. The second-through-seventh-placed teams all had one more win than the next team in their group in succession. In other words, the Sparks aren't getting many easy breaks on their schedule barring a seismic change in the WNBA landscape.
Since the WNBA has only 12 teams, the squads are packed with talent as opposed to other leagues where star players are more dispersed. The competition makes it tougher for Fisher, although his extensive basketball resume could be a huge asset for the team.
Furthermore, he's no longer locked into running a system that his team's president of basketball operations forced him to execute, which was the case in New York with Phil Jackson and the triangle.