Longueuil police said the woman was crossing at the intersection where the bike path meets Matte when she was hit by the car at around 8 a.m.
"We don’t know yet if she was facing a red or a green light before the impact," said Const. Martin Simard.
"This is what we are trying to establish at the moment."
There is a light for cyclists at the intersection of the bike path and the boulevard, he said.
The cyclist was taken to hospital where she was pronounced dead shortly after 9 a.m. The driver of the car was treated for shock.
A section of Matte Boulevard between Taschereau Boulevard and Highway 132 was closed for the police investigation.