Wirtz has been a big beneficiary of Kai Havertz’s transfer to Chelsea, making 35 appearances across all competitions and scoring seven goals.
The German youth international joined Leverkusen from Koln in January 2020.
He is seen as a future star of German football and received his first call up to the senior national team for March’s FIFA World Cup qualifiers, although he did not get playing time.
"It's not just his first call-up for Germany that shows that Florian has made fantastic progress in his 18 months here," said Leverkusen's managing director of sport, Rüdi Voller.
"His outstanding talent was there for all to see, and it meant we had high hopes when we signed him as a 16-year-old in early 2020.
"Then again, we didn't expect him to become a key figure in our first team! Given his young age, and the fact that he's still working towards his high school diploma, it's an extraordinary achievement. If he keeps this up, he will become a true leader in the next few years, one of the pillars of our team."
Wirtz added: "Everything at Bayer Leverkusen has been exactly as I expected, and what I was promised."
"I'm playing at a great club, one of the best in Germany, and I want us to aim for the highest possible goals in the coming years. I've already improved my football skills in a great team, and I just want to keep going. I want my performances to contribute to us winning titles here in the near future."
