Led by conductor Christopher Gray, the singers performed 'Can you feel the love tonight' by Elton John from The Lion King soundtrack.
The award-winning choristers finished their song and were met with a standing ovation from the audience and all the judges.
Judge, Simon Cowell said their performance was: "Absolutely stunning."
All four judges said yes to the choir going through to the next round of the talent show.
Truro Cathedral Choir has an unbroken tradition dating back to the 1880s when services took place in a wooden shed whilst Truro Cathedral was under construction.
Nowadays, the choir usually performs with its twelve adult professional singers made up of lay vicars and choral scholars, joined by either its eighteen boy choristers or its eighteen girl choristers.
For the ITV performance on Saturday, it was the boy and girl choristers performing.
Mr Gray told Simon Cowell on Saturday why they chose to take part in BGT: "I guess the show's done so much for variety and bringing it back into the mainstream and we think that something really traditional can be part of that."
In addition to singing at seven cathedral services each week, Truro Cathedral Choir perform regular concerts and broadcasts, including regular live broadcasts on BBC Radio 3 and has made several TV appearances over recent years.
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