Librarian Lottie, 19, claims she is the only one of the 12 Apprentice hopefuls who knows when the Second World War took place.
She revealed the "embarrassing blunder" by her boardroom rivals occured when they are asked to track down a pre-war book as part of the highly-anticipated buying task.
Lottie claims not one of her "idiotic and ignorant" peers are able to say what dates the war happened - leaving it for her to explain.
She reckons BBC1 viewers will be left feeling "insulted" when they see the contestants appearing not to know an "important part of British history".
Lottie, from Taunton, Somerset, said: "On this week's show I am the only one who knows when the Second World War was."
The youngest of the bunch vying for Sir Alan Sugar's £250,000 business plan investment, Lottie added: "It's very insulting to British people that they don't know such an important part of our history.
"I am disappointed in all of the candidates because no one else knew the dates. It shows how ignorant they all are to our history and respect for our country. It is very basic knowledge.
"We are often branded as idiots for going on The Apprentice but we do not help ourselves and have ourselves to blame.
"It's idiotic. It's as simple as that."
Lottie claims she has to "educate" the other contestants when the group are asked to track down a book dating before 1939 - the year WW2 started.
The alleged blunder is said to happen during tonight's episode which sees the contestants scour Oxford and Cambridge for hard-to-find items during the buying task.
Lottie published a Tweet ahead of the show asking viewers to look out for the "important reminder" about teaching children national heritage.
Fellow contestant, Lewis Ellis, replied to her comments admitting to "struggling" to know the wartime dates.
His Tweet, which has since been deleted, said: "We did struggle to recall the exact dates but I do recall WWII involved aggressive foreign policy by the Nazi party and an unprovoked attack … why does that sound familiar."
Lottie's father is Belgian and once fought for German armed forces, she said.
This comes just days after Lottie was accused of racism - following remarks she is alleged to have made in a WhatsApp message towards fellow contestant, Lubna Farhan.
Lottie is said to have told the 33-year-old to "shut up Gandhi".
The BBC called her words "wholly unacceptable" following an investigation.
Lottie has denied the allegations and has said she was "vilified".
After being accused - Lottie is now speaking out about the "embarrassing" contestants.
She said: "The fact that I had to explain made me feel like I was patronising them.
"It was embarrassing but I'm proud that I'm the youngest candidate and am intelligent, despite my age. They all appear to be ignorant to the history of our country."
Series 15 of The Apprentice continues tonighton BBC1 at 9pm.