He grew up with his parents in a small area of Glasgow called Maryhill.

He went to school in Milngavie just outside of Glasgow, where he met his best friend Daniel. He joined the local drama group, The Maryhill Youth Theatre, when he was 7. Biggerstaff performed "Augustus Gloop" in "Charlie and the Chocolate Factory", while friend Denis Moodie played "Grampa George" and "Mr. Teeve". Denis remembers their childhood fondly, recalling them watching Biggerstaff's Superman videos over and over, "not fair, he got to fly [in Harry Potter] and I didn't!"

By the age of 10, Biggerstaff was committed to acting. He auditioned for Macbeth, and ended up working for the Royal Shakespeare company. Encouraged, Biggerstaff joined the renound Scottish Youth Theatre (SYT) at the age of 11. He credits his current success to the ten years of experience he had there, performing in many parts and studying formal technique. It was at SYT he met Paul Kelly and others, who later performed with the band, playing bass guitar and vocals for two years before he left in November1999.
 

In 1996 (aged 13) Biggerstaff landed his first major role in the mini T.V. series, playing young Darren in "The Crow Road". However, it was in 1997 at the age of 14 when he got his break. Alan Rickman had watched Biggerstaff perfom in "Macbeth". Rickman was so impressed, he cast Biggerstaff in his new movie, The Winter Guest (starring Emma Thompson) as Tom, a mischievous school boy. This proved to be Biggerstaffs break: in a demanding yet comical part he demonstrated his potential. Soon afterward, Rickman recommended Biggerstaff to the London acting agency ICM. Within a week, the Harry Potter castings were being distributed. ICM originally recommended Biggerstaff for Percy Weasley, but during auditions the directors suggested that he looked at Oliver Wood, Gryffindor Quidditch Captain. Biggerstaff looked at the script and agreed.

In 1999, when Biggerstaff was 16, he was told he was going to have a baby sister, after growing up an only child. At seventeen, he became a brother to his little sister, Jenny.

The filming of "Harry Potter and the Sorcerer's Stone" continued from 2000 into 2001. In November the movie was released and became an instant hit. It soon became apparent that Biggerstaff's charm was 'sending girls' hearts a-flutter everywhere', aged a spritely 18 years old compared to the rest of the cast. There were more searches for the four-scenes-only supporting role, than for Daniel Radcliffe, the main role!

Personally-I highly resent that hehe

Since then, Biggerstaff has been working in England on the second Harry Potter movie, Chamber of Secrets. Biggerstaff is expected to have a bigger role in the sequel, with more challenging scenes for his character.

Biggerstaff's future looks bright. He is likely to be in the third movie of J.K. Rowling's series, "Harry Potter and the Prisoner of Azkaban". Since the release of the first Harry Potter movie, Biggerstaff has had more opportunities. He is currently considering scripts in L.A. and Melbourne with his agent.