Novae had not been widely considered as high-energy (>100 MeV) gamma-ray sources prior to the launch of the Fermi Large Area Telescope (LAT). In March 2010, the LAT made the first gamma-ray detection of a nova in the symbiotic binary V407 Cygni. The LAT observations uniquely probed the highenergy particle accleration mechanism in the environs of the V407 Cyg binary system consisting of a white dwarf and massive (red giant) companion.
Subsequently in June 2012, two more examples were discovered, Nova Sco 2012 and Nova Mon 2012, thus heralding novae as a new gamma-ray source class. In the latter case, the gamma-ray transient source was discovered first, followed by the optical confirmation of the nova. This showcases the all-sky monitoring capability of the LAT, and how novae can be found independently from traditional optical searches. We discuss the LAT detected gamma-ray novae together with observational limits on other optical novae over the first four years of the Fermi mission and reconsider the possible high-energy gamma-ray production mechanisms in novae in light of the new detections.