  We construct a complete basis of dimension-8 operators in the Low-Energy
Effective Field Theory below the Electroweak Scale (LEFT). We find there are
35058 dimension-8 operators in the LEFT for two generations of up-type quarks
and three generations of down-type quarks, charged leptons, and left-handed
neutrinos. The existence of this operator basis is a necessary prerequisite for
matching to the Standard Model Effective Field Theory at the dimension-8 level.
