The Hollywood siblings will play the London-based festival when it returns over the weekend of July 3 to 5, reported Digital Spy.
Charli XCX, Jess Glynne, MNEK, Maverick Sabre, DJ Mustard, Ms Dynamite, The Voice UK champ Jermain Jackman and Lethal Bizzle have also been added to the line-up.
Drake, Avicii and David Guetta were announced as headliners for New Look Wireless 2015 back in January.
Nicki Minaj, Kendrick Lamar, Jessie J, Labrinth, Clean Bandit, Duke Dumont, Childish Gambino, Wretch 32, Grandmaster Flash and Gorgon City are among the other acts confirmed to perform.