Castle Leslie hit the headlines in 2002 when Sir Paul McCartney married Heather Mills in the family church located on the estate, followed by a wedding banquet for 300 guests prepared by then executive chef, Noel McMeel. This secret was inadvertently divulged to the media by Sir Jack Leslie, who notoriously remarked on live television "it's on Tuesday, but it's a secret". More recently, in 2008, the castle was the venue of the launch of RAPID IRELAND (Rescue and Preparedness in Disasters, Ireland), a sister rescue charity to RAPID UK. The event was hosted by Sir Jack Leslie and Baron Oranmore and Browne, and attended by a number of ambassadors and dignitaries, including HRH The Duke of Gloucester.
Throughout the years many a famous face has frequented the house including Irish poet WB Yeats, Irish statesman General Michael Collins, Rolling Stones frontman Sir Mick Jagger, British astronomer Sir Patrick Moore and the Duc de Valentinois, not to mention various members of the Churchill family (to whom the Leslies are related).
The castle has had two recent brushes with reality TV. During RTE's Fáilte Towers, Brian Dowling chose Don Baker, Evelyn Cusack and Jennifer Maguire to take time out from the stress of the programme with a day and night's pampering at the castle, proprietor Sammy Leslie being one of the judges on the show.