The elliptic flow (v₂) of (anti-)³He is measured in Pb–Pb collisions at s_NN=5.02TeV in the transverse-momentum (p_T) range of 2–6 GeV/c for the centrality classes 0–20%, 20–40%, and 40–60% using the event-plane method. This measurement is compared to that of pions, kaons, and protons at the same center-of-mass energy. A clear mass ordering is observed at low p_T, as expected from relativistic hydrodynamics. The violation of the scaling of v₂ with the number of constituent quarks at low p_T, already observed for identified hadrons and deuterons at LHC energies, is confirmed also for (anti-)³He. The elliptic flow of (anti-)³He is underestimated by the Blast-Wave model and overestimated by a simple coalescence approach based on nucleon scaling. The elliptic flow of (anti-)³He measured in the centrality classes 0–20% and 20–40% is well described by a more sophisticated coalescence model where the phase-space distributions of protons and neutrons are generated using the iEBE-VISHNU hybrid model with AMPT initial conditions.