  Transverse-momentum-dependent parton distributions (TMDs) can be calculated
from first principles by computing a related set of Euclidean lattice
observables and connecting them via a factorization formula. This work focuses
on the leading-power factorization formula connecting the lattice quasi-TMD and
continuum Collins TMD for gluons. We calculate the one-loop gluon matching
coefficient, which is known to be independent of spin and exhibits no mixing
with quarks. We demonstrate that this coefficient satisfies Casimir scaling
with respect to the quark matching coefficient at one-loop order. Our result
facilitates reliable lattice QCD calculations of gluon TMDs.
