The Cycle St Giles Autumn bike ride was due to take place over the weekend from October 17 and 18.
It was adapted to adhere to safety guidelines amid the pandemic.
However the charity, based in Lichfield, says rising Covid-19 rates and new lockdown restrictions has resulted in the event being cancelled.
Elinor Eustace, director of fundraising at St Giles Hospice, said: "We would truly like to say sorry to every one of our wonderful supporters who signed up to take part in Cycle St Giles Autumn this year.
"Our fundraising team did an incredible job in planning a Covid-secure event with extra measures in place to ensure the health and safety of every participant, volunteer and member of staff.
"However, as a healthcare charity working with the most vulnerable in our society we have a duty to act in a socially responsible way and we don't feel that running a mass participation event is the right thing to do at this time with infection rates increasing and additional restrictions being enforced both locally and nationally."