The singer and entertainer replaced the show's co-creator Sara Gilbert when she quit the programme last summer, and now Marie is leaving to focus on other projects, including a new show.
"Marie is a consummate professional, and we thank her for sharing her personal experiences, insight, as well as incredible talents, with our audience," a statement from network bosses at CBS to Deadline reads. "We will miss her humour, kindness and good nature, and wish her much success in her future endeavours."
Osmond's departure comes weeks before the show returns to TV for an 11th season. Her co-hosts Eve, Carrie Ann Inaba, Osbourne, and Sheryl Underwood are all expected to return.