Saint Killian's unit was formed in 1940 by founding member Con Murphy.The unit was founded due to a lack of recreational facilities for young people in Clondalkin.
The scout unit in Clondalkin got off to a proper start on St. Patrick's Day in 1940 with the 78th troop's first investiture. From the original 12 members the troop grew steadily for the next 30 years.
Due to rising membership the 79th was formed in 1969. and is still going strong to this day.
These days Saint Killian's has one beaver section,one Macaoimh,(cub-scout) section,one scout section and one venture section comprising to approximately 100 young members