The original movie attracted 9.4m viewers in the UK in 2006, and Disney hope to tap into this tween fan base with a mix of TV, press, online, outdoor and retail activity.
Promotion is already live with a 'High School Musical 2' nationwide bus tour and talent competition, which built early awareness and hype in the franchise's massive fan base. The film's TV premiere on the Disney Channel has also been advertised as "coming soon" on cable and satellite throughout August.
The movie's first UK screening will be at a VIP premiere at The O2 on September 2, and it will air on the Disney Channel on September 21.
Rob Gilby, managing director of Disney Channel UK, said: "The premiere of 'High School Musical 2' marks 18 months of global 'High School Musical' mania amongst tweens. Our campaign will let them connect with 'High School Musical' via as many platforms as possible."
Disney is now running TV spots on terrestrial and digital channels and will begin print ads on September 5.
Radio ads will roll out on September 9 on stations popular with the movie's fan base, such as Smash Hits and The Hits, and around radio chart Hit 40 UK.
Disney will also build on the viral success of the Disney Channel website by running banner ads across teen sites such as Sugar and Trouble.
The campaign for the first movie reached almost 20m children in 2006, and played a huge part in boosting Disney Channel UK's audience by 35%.
The marketing campaign will also promote the 'High School Musical 2' soundtrack. Sales of the original soundtrack outstripped Lily Allen, Robbie Williams and Keane in 2006.