Season 13 is set to air on CBBC and BBC iPlayer from January 17.
The actress, who has played Tracy Beaker since 2002, is making a return to the role in the popular series.
Ms Harmer is also directing an episode of the new series (Image: Supplied) The character of Tracy Beaker has been an integral part of the show’s narrative, which revolves around life in the care system.
Ms Harmer said: “It is so good to be back and making a cameo as Tracy – she’s been a part of my life for over 20 years now – but I’d quite happily play her forever.
“This series of The Dumping Ground will not disappoint, we’ve got some fantastic storylines and some incredibly talented actors joining the cast.”
In addition to reprising her role as Tracy Beaker, Ms Harmer has also taken on the responsibility of directing an episode.
The actress, who has been part of the show since its inception, expressed her enthusiasm for her new role.
She said: “The production team do such an amazing job nurturing them and they have really supported me behind the camera too, it’s such a special production to be working on.
“I loved being behind the scenes for an episode – it was very different being sat in the director’s chair but I enjoyed every single second of it… it felt like that was where I was meant to be.”
The Dumping Ground has been filmed in the North East for 12 years, including most recently in Hexham.
The series, which is inspired by Jacqueline Wilson’s books, follows the lives of a group of young people living in a children’s home.
It combines the anarchic activities of the group with tough and emotional storylines.
The show has a track record of on-screen diversity, aims to highlight new British talent, and focus on homegrown storytelling.
BBC Children’s and Education and BBC Studios, producers of The Dumping Ground, collaborate with North East Screen on the series.
The production spans Dani Harmer’s journey from her acting debut in the Tracy Beaker series to her first role as a director, while also featuring regional talent such as Amy Leigh Hickman and Mia McKenna Bruce.
The Dumping Ground series 13, commissioned by BBC Children’s and Education and made by BBC Studios Kids & Family Productions, will air on CBBC and BBC iPlayer from January 17.