The Norfolk Young Enterprise Showcase - held at Open Norwich on Tuesday, April 24 - displayed the work of 10 businesses, and marked the culmination of the programme.
It saw the students create a product or service, market and sell it, produce financial reports and take part in trade fairs.
Of the final 10, the joint winners were announced as Tembo from Norwich High School for Girls and Varioco from Norwich School.
Tembo is a brand of urban streetwear, which Varioco designs and sources crystal glasses showing the Norwich skyline.
The joint winter will represent Norfolk at the regional showcase at the University of East Anglia on June 13.
Patricia Hagan, Young Enterprise Regional manager, said: “Students from around the age of 15 to those in sixth form typically take part. We have some younger students represented here and they’ve done tremendously well, they’ve not been phased by the process at all.”