The journalist and broadcaster joins Max George, Jonathan Creek actress Caroline Quentin and former NFL player Jason Bell who were all announced on Tuesday.
Ranvir said: “The initial feeling of being confirmed for Strictly is one of complete terror – feels like embarking on a rollercoaster, where you really want to do it but you are equally scared.
“Hopefully after the first dance I will feel exhilarated rather than sick!”
George, 31, Quentin, 60, and Bell, 42, were all unveiled on Tuesday’s The One Show.
Radio presenter Clara Amfo and Olympic boxer Nicola Adams will also feature on this year’s series, with the latter set to be paired with a female dancer in a first for the show.
Nicola, who won gold at both the London 2012 Olympics and Rio 2016, is dating Ella Baig and has been praised as an LGBTQ role model.
The show will be shorter this year because of precautions surrounding the coronavirus pandemic.
Bruno Tonioli will be missing from the judging panel for Saturday night shows when the series returns later this year because he is in Los Angeles, where he is on the panel for the US version of the show, Dancing With The Stars, and will not be able to travel back and forth.
However, he will be involved remotely in the Sunday night results show each week and will return to the show full-time towards the end of the series.
Shirley Ballas, Motsi Mabuse and Craig Revel Horwood are all expected to return to their judging roles.
The show would usually return at the end of September, with the final just before Christmas, but its 2020 launch is expected to be slightly delayed.