The woman, who said she was called Karen O'Kane, spent £469 on her four-tier, bespoke, designer cake for her wedding this weekend.
But cake makers Stephen Whyteside and Michael Burns, owners of Special Days bakery in Uddingston, haven't heard from her since she made the booking.
And today they issued a desperate plea for the bride-to-be to come forward in time for her ceremony on Saturday.
Stephen, said: "In 21 years, we've made cakes for thousands of brides, but we've never, ever, had a situation like this.
"The whole thing just makes no sense and we have no idea what has happened to this bride, or how to track her down.
"The phone number she left with us is dead, her address is incorrect, and her venue is hosting a wedding on Saturday – but it isn't her's.
"We really can't figure out what is going on, especially when the bride paid the full price for the cake in May.
"We've tried everything possible to try and track her down.
"Our bride made the original booking at a wedding fayre at SECC, back in February.
"She appeared to be like any normal, happy bride-to-be. Nothing stood out about her.
"We really have no idea where she is. I just hope nothing bad has happened to her."
Special Days' bakers are hoping that Karen –or someone who knows her – will get in touch before Saturday and solve the mystery.
Stephen, added: "I'll have the cake ready for Saturday morning and there will be a driver on standby.
"I just really hope we track her down in time – I've got my fingers crossed."
Are you our mystery bride – or do you know who she is?
If so, contact 0141 302 6522 or email firstname.lastname@example.org