We report the detection of γ-ray pulsations from the high-magnetic-field rotation-powered pulsar PSR J1119-6127 using data from the Fermi Large Area Telescope. The γ-ray light curve of PSR J1119-6127 shows a single, wide peak offset from the radio peak by 0.43 0.02 in phase. Spectral analysis suggests a power law of index 1.0 0.3+0.4-0.2 with an energy cutoff at 0.8 0.2+2.0-0.5GeV. The first uncertainty is statistical and the second is systematic. We discuss the emission models of PSR J1119-6127 and demonstrate that despite the object's high surface magnetic field - near that of magnetars - the field strength and structure in the γ-ray emitting zone are apparently similar to those of typical young pulsars. Additionally, we present upper limits on the γ-ray pulsed emission for the magnetically active PSR J1846-0258 in the supernova remnant Kesteven 75 and two other energetic high-B pulsars, PSRs J1718-3718 and J1734-3333. We explore possible explanations for the non-detection of these three objects, including peculiarities in their emission geometry. © 2011 The American Astronomical Society. All rights reserved.