The figure of the Prime Minister will join fellow world leaders, including US President Donald Trump and German Chancellor Angela Merkel, at the London attraction's Downing Street set.
Mrs May is depicted stepping out of the Number 10 doorway wearing a red power suit, donated and fitted by British designer Amanda Wakeley.
It is the same outfit she wore on election night and for her first meeting with Mr Trump, whose figure will stand next to hers.
Sculptors spent four months crafting the likeness of Mrs May, which was unveiled on Wednesday.
She is the latest in a long line of British prime ministers immortalised at the attraction since 1855.
Edward Fuller, general manager of Madame Tussauds London, said: "Whilst there may be no end in sight to Brexit talks, it has only taken our highly talented team of sculptors four months to create this phenomenal likeness of Theresa May.
"Mrs May is set to leave a lasting impression on British politics, and I'm confident the same will be said about her figure and our visitors.
"It's clear the next few months aren't going to be easy as she guides our country through some difficult decisions, but whilst her policies may be questioned we can guarantee our wax figure of the Prime Minister is most definitely strong and stable."