The rider, on a lime green bicycle, was involved in a collision with the National Express West Midlands bus in Bloxwich Road, Bloxwich, just before 4pm on Thursday.
The 38-year-old was taken to hospital but died on Saturday night.
The driver of the bus stopped at the scene and is assisting police with enquiries.
A spokesman for West Midlands Police said on Sunday: "A cyclist has died after colliding with a bus on Bloxwich Road, Walsall on Thursday, July 22.
"The 38-year-old man was taken to hospital and sadly died as a result of his injuries on Saturday night.
"Our thoughts are with his family as they are being supported by specialist officers.
"The bus driver stopped at the scene and is assisting our enquiries as we review CCTV."
A large cordon was set up in the road on Thursday after the bike became stuck underneath the bus, which had a smashed windscreen.
The cyclist’s clothing could also be seen on the road behind the bus.
Witnesses or anyone with information is urged to call West Midlands Police on 101, quoting incident log number 2899 of July 22.
Alternatively, contact Crimestoppers anonymously on 0800 555111 or at crimestoppers-uk.org