According to Official Guinness Records,
The greatest number of walking golfers to complete a full round on the same course within 24 hours is 632, and was achieved by The First Tee of Ireland, at Faithlegg Golf Club, Waterford, Ireland from 22 - 23 June 2009.
The record attempt was made to raise money for The First Tee of Ireland charity.
For a complete list of 2009 records, please visit 2009 Guinness Records in Ireland.