The star, 32, shared the news on his Instagram on Sunday as he apologised to fans hoping to see him today and tonight.
Sharing a video from his hotel bed, John said he’s now waiting for a result of a PCR to come back after he tested positive on a lateral flow.
Strictly star John Whaite pulls out of tour
In the video, he said: “Hi everyone, little bit of bad news I’m afraid.
“A lateral flow this morning has come back positive so I now have to sit here in this glamorous captivity until a result of a PCR come back – and I’m hoping they come back negative because I feel fine.”
He continued: “I’m triple jabbed, I had coronavirus in summer, so I’m hoping it’s just a false positive.
What else did John say?
“But that does mean of course that I won’t be able to perform today or tonight in Glasgow.
“I am very, very, very, very, very sorry if anyone was hoping to see me shake my thing on the dance floor because I just won’t be there shaking it.”
He quipped: “I’ll be in my hotel room – probably still shaking it – but that isn’t something I wish the world could see because it isn’t pretty, darling.
“When you’re not in sparkles and sequins, it ain’t pretty.”
Concluding the video, John said: “Anyway, I’m sorry I can’t be there. I hope you enjoy the show nonetheless, and good luck to all my friend who are in the show today.
“I’m sorry I’m letting you all down.”
John was meant to be performing in Glasgow tonight at the OVO Hydro arena.
The news comes just days after John and his professional partner Johannes Radebe won a show in Manchester.
The Strictly tour Instagram page announced at the time: “The winners for the first show in Manchester were… John and Johannes!
“Rose [Ayling-Ellis] and Giovanni [Pernice] were this afternoon’s runners up. Congratulations everyone!”
Fans were thrilled as one gushed: “Best news ever! This has absolutely made my weekend!”
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