Texas announced the move on Friday. Banister, 54, owned a 325-313 record during his tenure as Rangers skipper. He was 2015 American League Manger of the Year, after leading the team to an 88-74 record that season, a 21-win improvement from the previous season.
The Rangers also announced that bench coach Don Wakamatsu has been named the team's interim coach for the remainder of the 2018 season, effective immediately.
"I informed Jeff Banister of our decision earlier today," Rangers president of baseball operations and general manager Jon Daniels told reporters. "I want to thank Jeff for his dedication and efforts with the Texas Rangers over the last four years. This organization is very appreciative of what he has contributed to the club on the field and in the community."
"This was not an easy decision and comes after a long period of evaluation. However, we feel that a change in the leadership of our Major League club is necessary as we move forward. Once this conclusion was reached, I felt it was appropriate to make the move now. On behalf of the entire organization, I wish Jeff and his family the best."
Texas (64-88) sits in last place in the American League West heading into a weekend series with the Seattle Mariners. The first game of the series is at 8:05 p.m. on Friday at Glove Life Park in Arlington, Texas.