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We present the first application of mid-infrared Period-Luminosity relationsto the determination of a Cepheid distance beyond the Magellanic Clouds. Usingarchival IRAC imaging data on NGC 6822 from Spitzer we were able to measuresingle-epoch magnitudes for sixteen long-period (10 to 100-day) Cepheids at3.6um, fourteen at 4.5um, ten at 5.8um and four at 8.0um. The measured slopesand the observed scatter both conform to the relations previously measured forthe Large Magellanic Cloud Cepheids, and fitting to those relations givesapparent distance moduli of mod{3.6} = 23.57 +/- 0.06, mod{4.5} = 23.55 +/-0.07, mod{5.8} = 23.60 +/- 0.09 and mod{8.0} = 23.51 +/-0.08 mag. Amulti-wavelength fit to the new IRAC moduli, and previously published BVRIJHKmoduli, allows for a final correction for interstellar reddening and gives atrue distance modulus of 23.49 +/- 0.03 mag with E(B-V) = 0.26 mag,corresponding to a metric distance of 500 +/-8 kpc.

The Cepheid Period-Luminosity Relation (The Leavitt Law) at Mid-Infrared Wavelengths: III. Cepheids in NGC 6822