  We present constraints on violations of Lorentz Invariance based on Lunar
Laser Ranging (LLR) data. LLR measures the Earth-Moon separation by timing the
round-trip travel of light between the two bodies, and is currently accurate to
a few centimeters (parts in $10^{11}$ of the total distance). By analyzing
archival LLR data under the Standard-Model Extension (SME) framework, we
derived six observational constraints on dimensionless SME parameters that
describe potential Lorentz-violation. We found no evidence for Lorentz
violation at the $10^{-6}$ to $10^{-11}$ level in these parameters.
