Taoiseach Enda Kenny is one of 9,000 cyclists participating in the Ring of Kerry cycle today.
The event covers 112 miles and organisers hope to raise €1m for charity.
This year's event is being dedicated to cyclist Paud O'Leary who died in a hit-and-run incident, in Gneeveguilla last Sunday while training for the event.
No arrests have been made and gardaí are still investigating the incident.
Speaking to Radio Kerry, Mr Kenny said he hopes everyone has a fun day.
"I hope that everyone has a very enjoyable day," Mr Kenny said.
"I know that this is tinged with tragedy on account of the death in Gneeveguilla… but it's for a very worthy cause.
"I understand that it would expect to raise nearly €1m which is an extraordinary demonstration of commitment by everybody.
"I hope everybody gets around safely and that they enjoy themselves."