Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search ( at 3.1 GHz ) in the error circle of the EGRET source 3EG J1027-5817 . The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source . We report here the discovery of \gamma -ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope ( LAT ) on the Fermi Gamma-Ray Space Telescope . The \gamma -ray light curve shows two sharp peaks having phase separation of 0.460 \pm 0.004 , trailing the very narrow radio pulse by 0.200 \pm 0.003 in phase , very similar to that of other known \gamma -ray pulsars . The measured \gamma -ray flux gives an efficiency for the pulsar of \sim 10 - 20 \% ( for outer magnetosphere beam models ) . No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission . However , the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources , one of which is now identified as PSR J1028-5819 .