Banjo and his wife Francesca Abbott met as teenagers and married in 2015, but the dancer revealed in an Instagram Stories post that the couple went their separate ways 18 months ago.
He wrote: "After being together for over 16 years, since we were teenagers, this is not a decision that has been taken lightly.
"It has not been easy and the processing of the situation has not been fast by any means. But we feel that as we approach the new year it is the time to share this news with others."
Banjo continued by promising that he and Abbott's "main focus" will be their children Rose and Micah, who they will co-parent "in a happy and healthy environment".
He added: "Sometimes after so many years people just move in different directions, but we do so lovingly and we continue to try and be both the best parents possible and the best of friends to each other.
Read more: Ashley Banjo is working on a Diversity movie
“We have always been private with our personal lives, so we kindly ask that everyone please continue to respect that privacy. We won’t be making any further comment on the situation."
Abbott, who works as a member of the dance troupe’s management team, posted the same statement to her Instagram story.
The couple announced their engagement in October 2014 and wed the following year. They share two children, daughter Rose and son Micha.
Banjo rose to fame when he led Diversity to victory on the third series of Britain's Got Talent in 2009, beating favourite Susan Boyle.
In August 2020, Banjo was announced as Simon Cowell’s replacement on the BGT judging panel after the music mogul injured himself riding an electric bike, bringing his career full circle.
He is also a member of the Dancing On Ice judging panel and was made an MBE in the 2022 New Year Honours for services to dance.
Watch: Ashley Banjo is uncertain of his future on Dancing On Ice