Bisciotti also announced that assistant general manager Eric DeCosta will replace Newsome.
The 61-year-old Newsome has been the Ravens' GM since 2002.
After a Hall of Fame career with the Cleveland Browns as a tight end, Newsome joined Cleveland's front office in 1991.
He remained part of the franchise's front office when it moved to Baltimore in 1996, and he helped construct the 2000 roster that won Super Bowl XXXV.
Newsome became the NFL's first African-American general manager shortly thereafter, and he won his first Super Bowl as a GM in the 2012 season when the Ravens beat the San Francisco 49ers in Super Bowl XLVII.
During Newsome's tenure as general manager, the Ravens have reached the playoffs on eight occasions and won four AFC North division titles.
The 46-year-old DeCosta has been part of the Ravens since their move to Baltimore in 1996. He was the director of college scouting and director of player personnel before getting elevated to assistant general manager in 2012.
Newsome's final opportunity to win a second Super Bowl as a GM will come next season, as Baltimore will look to bounce back from a 9-7 campaign in 2017 that saw it narrowly miss the playoffs.