Jennings, 27, averaged 8.6 points and a team-high 4.9 assists in 24.6 minutes per game during his only season with the Knicks. He signed a one-year, $5 million contract during the offseason to back up Derrick Rose.
Jennings recently told New York (24-35) he wanted to play for a title contender, a source told The Undefeated's Marc J. Spears.
The Knicks looked into trading Jennings after the point guard expressed a desire to move on, sources told ESPN, but no deal emerged prior to the deadline.
Knicks coach Jeff Hornacek intimated that the decision to waive Jennings was mutual. Jennings was looking for more playing time -- a demand the Knicks couldn't fulfill, the coach said. The Knicks were looking to open a roster spot for guard Chasson Randle, whom they signed on Monday.
"Maybe this gives him an opportunity to get somewhere where he can play some more minutes," Hornacek said.
The Washington Wizards have an interest in Jennings, sources told ESPN's Chris Haynes.
Jennings tweeted thanks to the Knicks on Monday morning.
Thank you to all the Knicks fans for the love all year long, and thanks to my teammates and the organization.— Brandon Jennings (@brandonjennings) February 27, 2017
Playing in the Mecca was an amazing experience and I'm looking forward to being back on the court soon playing the game that I love.— Brandon Jennings (@brandonjennings) February 27, 2017
Hornacek pushed back against the notion that the Knicks, four games out of eighth place in the Eastern Conference entering play Monday, were losing intentionally to improve their chances to land a top pick in the draft lottery.
"As a team we're not thinking about losing," he said. "If that's what it comes down and then we get a different draft pick, we'll worry about it then. We're still trying to win. Because Brandon was waived doesn't mean that we're not trying to win these games. We feel Ron Baker can fill right in."
Randle, 24, signed for the rest of this season and is expected to have a partial guarantee for next season, a source said. He played well for the Knicks in the preseason, but the team waived him after he suffered a broken orbital bone shortly before the regular season began.
Randle is familiar with the Knicks' triangle offense, which the club has emphasized more often after the All-Star break. He is expected to be the second lead guard off the bench, behind Baker.
Hornacek said that with Jennings gone, Rose's minutes might increase. Rose entered play Monday averaging 32.2 minutes per game.
ESPN's Ian Begley contributed to this report.