The 52-year-old Canadian superstar was singing a track from her new album called Now, but some people were not convinced that she was singing live leading to speculation on social media.
“Shania Twain on #Strictly is the worst miming I've seen since Top Of The Pops in the 80s #MakeItStop,” said one frustrated audience member.
As another posted a GIF from the pop star’s video Don’t Impress Me Much, along with the tweet: “Shania Twain miming on @bbcstrictly #StrictlyComeDancing2017 #strictly #StrictlyComeDancing.”
A third raged: “I am so mad that Shania Twain was lip syncing on #Strictly.”
However, others defends Shania and blamed the BBC technical department for the sound quality with a Strictly Come Dancing fan explaining: “#Strictly also @RitaOra was AMAZING tonight !!! The sound was crappy for shania aswell as Rita but rita handled it better i think :) [sic].”
“Dear BBC. Please can you turn the lead vocals up? #Shania #Rita #strictly sound,” a second added.
BBCViewers not impressed with Shania Twain's singing on Strictly Come Dancing
BBCSinger Shania Twain was slammed by Strictly Come Dancing viewers
It takes a sincere determination, it takes an amazing work ethic, and a love of each an every dance that you do,
Strictly Come Dancing judge Shirley Ballas
Along with Shania’s performance, former X Factor judge Rita Ora took performed during the musical interlude on the launch show.
Tonight’s launch show saw the celebrity line-up finally getting paired up with their Strictly Come Dancing pros as the BBC juggernaut got underway for another year.
Ruth Langsford was teamed up with Anton Du Beke, while Good Morning Britain star Charlotte Hawkins landed Brendan Cole.
BBCShania Twain got a mixed reception on social media after her Strictly Come Dancing performance
BBCThis year's Strictly Come Dancing line-up
Fans of the dance competition were also introduced to new head judge and Len Goodman’s replacement Shirley Ballas, who explained her expectations of the stellar line-up.
"It takes a sincere determination, it takes an amazing work ethic, and a love of each an every dance that you do,” she told hosts Tess Daly and Claudia Winkleman.
The launch programme also paid tribute to the late, great Sir Bruce Forsyth who died last month. It was clear that host Tess was deeply saddened by the loss and she was seen breaking down during the programme following a poignant video montage.
Strictly Come Dancing airs on BBC One on September 23.