The celebrity contestants have already been paired with their professional partners in a pre-recorded launch show due to air on BBC One on Saturday, 18 September, at 7.45pm.
A Strictly spokesperson confirmed to Yahoo UK: “A professional dancer has tested positive for COVID-19 however this didn’t affect recording of the launch show which airs this Saturday.
"We are following government guidelines to ensure the safety of all on the show.”
According to The Sun, the celebrity contestant has tested negative but will be unable to rehearse with their dance partner, who must isolate for 10 days ahead of the live shows which begin on Saturday 25 September.
Taking part this year are McFly's Tom Fletcher BBC Breakfast star Dan Walker, Gordon Ramsay's daughter Tilly Ramsay, Olympic swimmer Adam Peaty, EastEnders stars Nina Wadia and Rose Ayling-Ellis and former Bake Off winner John Whaite.
Judges Craig Revel Horwood, Motsi Mabuse and Shirley Ballas will be back, but Anton Du Beke will be filling in for Bruno Tonioli.
Tonioli is unable to take part because of the complications of travelling between the UK and the US, where he judges Dancing With The Stars, amid the COVID pandemic.
As part of the limits placed on the live shows last year, if a contestant or dancer tested positive for COVID they were forced to pull out of the competition.
This led to boxer Nicola Adams and her professional partner Katya Jones withdrawing after just three weeks when Jones tested positive. The couple had made history as Strictly's first same-sex pairing.
The shows were all filmed on site at Elstree Studios in Borehamwood, north London, with no studio audience present, and the professional group numbers were filmed in advance.
Watch: Pro dancer Janette Manrara is the new host of Strictly: It Takes Two