  We calculate total and differential cross sections for the pair production,
at the Large Hadron Collider, of exotic leptons that could emerge from models
with vector-like leptons and in Type-III seesaw scenarios. Our predictions
include next-to-leading-order QCD corrections, and we subsequently match them
with either parton showers, or threshold resummation at the
next-to-next-to-leading logarithmic accuracy. Our results show an important
increase of the cross sections relative to the leading-order predictions,
exhibit a distortion of the shapes for various differential distributions, and
feature a significant reduction of the scale uncertainties. Our predictions
have been obtained from new FeynRules model implementations and associated UFO
model libraries. This completes the set of next-to-leading-order
implementations of new physics models featuring extra leptons that are publicly
available on the FeynRules model database.
