The newbie star, who made his name in 'Chronicle' and has small parts in 'Lawless' and 'Lincoln', joins Andrew Garfield and Emma Stone in the superhero franchise, reported Daily Express.
"Dane is an exciting and extraordinary young actor and he is a fantastic addition to our cast," Webb said.
Webb later confirmed the news via twitter, saying, "Meet Harry Osborn. So excited to have him on board."
Dane replied saying, "To say I'm excited is an understatement. #HarryOsborn #ASM2'', before being inundated with positive comments from fans of the Marvel comic book franchise."
Actors Jamie Foxx and Shailene Woodley have also been confirmed as Electro and Mary-Jane Watson respectively.
"The Amazing Spider-Man 2" will be released in the UK on April 18 2014.