Knocklong is a small village in County Limerick, Ireland. It is 29 km south-east of Limerick city, on the main Limerick to Mitchelstown to Cork road. The population was 256 at the 2016 census. The village is in a civil parish of the same name.

On 13 May 1919, a captured Irish Republican Army (IRA) member, Seán Hogan, was rescued from a train by his comrades while being guarded by four armed Royal Irish Constabulary (RIC) officers. Two of the RIC officers were killed and several IRA volunteers were wounded. The rescue took place on Hogan's 18th birthday, while the Cork-bound train stopped at Knocklong station in County Limerick. It was undertaken by three of Hogan's comrades from the 3rd Tipperary Brigade of the IRA and five members of the Galtee Battalion of the East Limerick Brigade. Hogan was one of the most wanted men in Ireland at the time of his rescue, due to his role in the Soloheadbeg ambush and would almost certainly have been executed.