5th Engineer Regiment is a Reserve unit of the Royal Australian Engineers. Originally raised as the "5th Combat Engineer Regiment", it is based in Holsworthy, Sydney, with one of its sub-units based at the multi-user depot HMAS Harman, in Canberra.In late 2013, the regiment was reorganised, when two sub-units – 101st Construction Squadron and the Littoral and Riverine Survey Squadron – were transferred from the 21st Construction Regiment, following the decision to disband that unit.