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tokens: by the interaction of the supernova (SN) ejecta with the circumstellar medium (e.g. Ofek et al. 2007 ; Quimby et al. 2011c ; Chevalier Irwin 2011 ), (ii) pair-instability driven ( Gal-Yam et al. 2009 ; Gal-Yam Leonard 2009 ), or (iii) neutron-star driven ( Kasen Bildsten 2010 ; Dessart et al. 2012 ; Kotera et al. 2013 ; Metzger et al. 2014 ; Murase et al. 2015 ; Suzuki Maeda 2017 ). Given the variety of observed spectra, it is plausible that different processes are at play in different objects (e.g. Gal-Yam 2012a ; Nicholl et al. 2014 ). Interestingly, scenarios (i) and (iii) predict bright associated γ -ray emission in the GeV to TeV range ( Murase et al. 2011 , 2014 , 2015 ; Katz et al. 2012 ; Kotera et al. 2013 ). The search for such γ -ray emission with the Fermi Large Area Telescope (LAT) data is the scope of this paper. In the most conventional model (scenario i) SLSNe are powered by the interaction between the SN ejecta and a massive, optically thick circumstellar medium ( Smith McCray 2007 ; Smith et al. 2008 ; Miller et al. 2009 ; Benetti et al. 2014 ). SN2003ma and SN2006gy for example seem to be explained well by this phenomenology ( Smith McCray 2007 ; Ofek et al. 2007 ; Smith et al. 2010 ). Several authors ( Murase et al. 2011 , 2014 ; Katz et al. 2012 ) have demonstrated that a collisionless shock could then be formed and would host efficient cosmic-ray acceleration leading to non-thermal emission from radio-submillimeter to γ -rays. In the GeV range, this emission can escape from the system without severe attenuation, for specific shock velocities (about 4500–5000 km s −1 ) ( Murase et al. 2015 ), and at late times after the shock breakout. Ackermann et al. (2015) searched for this specific radiation with the LAT at the location of core-collapse SNe (Types IIn and Ib), with standard luminosity, spanning typical time windows of a few months to a year starting from the optical luminosity peak. No detection was reported and model-independent flux upper limits were derived. A fast-rotating central neutron star releasing its rotational energy into the SN ejecta could also drive SLSNe (model iii; e.g. Kasen Bildsten 2010 ). The rotation period has to be close to milliseconds to transfer significant energy to the ejecta. The strength of the initial dipole magnetic field of the star sets the timescale over which the energy is injected (a stronger field leads to faster decline). Magnetars ( B ~ 10 15 G) have thus been proposed as central engines for SLSNe ( Kasen Bildsten 2010 ; Dessart et al. 2012 ). Pulsars with millisecond periods at birth and milder dipole magnetic fields B ~ 10 13 G would also lead to bright peaks as well as a high-luminosity plateau lasting for several months to years ( Kotera et al. 2013 ; Murase et al. 2015 ). These authors further calculated that the young neutron-star wind nebula would present a bright X-ray and γ -ray peak, respectively, through synchrotron radiation and inverse Compton (IC) scattering,