The 19-year-old forward joined Dortmund from Manchester City in 2020 and made his first team debut in April 2022.
Bynoe-Gittens had a bigger involvement in the Dortmund side last season, making 20 appearances across all competitions and scoring three goals.
"Jamie is a prospect for the future. A winger with incredible pace, who constantly looks to get into one-on-one situations, and displays his technical ability in doing so, can create goalscoring opportunities for his teammates or can look to shoot himself," said Borussia Dortmund sporting director Sebastian Kehl.
"We are convinced that his development is far from complete, and we are pleased that Jamie has decided at this early stage to commit his long-term future to BVB, despite great interest from several other big European clubs."
Bynoe-Gittens commented: "I am proud that Borussia Dortmund have given me the opportunity to sign such a long-term contract. Even during the difficult times for me in the past months due to injury, I have always felt the belief and trust of the club. I feel incredibly comfortable in this team, in this city, in this stadium.
"BVB were always my first point of contact because they have shown over many years that they give young players playing time at the highest level, if they perform convincingly. I wish to take the next step together with my club and want to help my team on the pitch with goals, assists and hard work."
