Writer/Director Henry Fox attended La Costa Canyon High School (shown in the film). For casting, he hired actors who attended the same school (nearly a decade after he graduated).
Quinn Hitchcock (Wayne) went to the same elementary school as Henry Fox - Quinn was in kindergarten while Henry was in 8th grade.
Writer/Director Henry Fox auditioned the principle actors during their stage productions throughout the school year, not telling them they were being auditioned based on their stage performances. Their first production was A Love of Three Oranges (which they competed at California Educational Theatre Association). Their second production was Les Miserables won awards from The National Youth Arts Awards. Alondra Alvarez and Aubrie Pache won awards for their performances.
Brad and Dale Hawthorne proved challenging to cast. Writer/Director Henry Fox originally cast 2 actors who dropped out a week before filming. After several unsuccessful auditions, John Wilcox was cast during the final week of production. John Wilcox suggested his friend, Chris Pegut to play Dale.
Having to film Wishbones over the summer due to financial and legal reasons, Writer/Director Henry Fox asked all the actors who auditioned or were interested to be background actors. Not realizing that most high school students go on vacation, Henry had to use anyone that was available including his production assistants, Jensen Hasburgh and Mary Harris. They can be seen throughout the film. Jensen played Jasmine and her sister in the gym and Mary played Naomi.