The pharmaceutical firm is the sixth company the European Union has landed a deal concerning the supply of a coronavirus vaccine.
"Our chances to develop and deploy a safe and effective vaccine have never been higher, both for Europeans here at home, or for the rest of the world," European Commission president Ursula von der Leyen said.
"To defeat coronavirus anywhere, we need to defeat it everywhere."
Brussels has previously signed deals with Sanofi-GSK, Johnson & Johnson, Curevac, Moderna and with AstraZeneca to be ready to procure doses quickly if and when any of the companies develop a safe and effective coronavirus vaccine.
"We are optimistic that among these candidates there will be a safe and effective vaccine against Covid-19 to help us defeat this pandemic," the EU health commissioner, Stella Kyriakides, said.
In a statement, BioNTech said the agreement includes an option for another 100 million doses.
Deliveries could start as soon as the end of 2020, if the labs successfully clear the various tests phases.