Adrian Mullan was killed in the collision involving a van on the Redcastle to Gleneely Road.
A second cyclist was also injured in the crash and was taken to Letterkenny General Hospital. However, his injuries are not thought to be life-threatening.
Mr Mullan was a member of the Foyle Cycling Club.
The 42-year-old cyclist, who died in County Donegal on Saturday, was a father of three from Londonderry.