In　this　work,　we　demonstrate　a　hybrid　cold　sintering/spark　plasma　sintering　(CSP-SPS)　process　to　densify　ZnO　ceramic　with　controlled　grain　growth.　The　densification　of　ZnO　is　initially　activated　at　85　°C,　and　high　densities　(＞98%)　are　achieved　at　200–300　°C　in　only　5　min　with　a　low　assisted　pressure　of　3.8–50　MPa.　The　microstructure　of　ZnO　grains　experiences　a　mild　coarsening　from　~205–680　nm　during　the　CSP-SPS.　In　comparison,　a　much　higher　temperature　(＞770　°C)　is　required　to　sinter　ZnO　ceramic　via　SPS,　and　the　grain　size　exhibits　an　obvious　overgrowth　to　~10　µm.　The　calculated　apparent　activation　energy　of　grain　growth　using　CSP-SPS　is　69.3　±　6　kJ/mol,　which　is　much　lower　than　that　of　SPS　samples　with　296.8　±　59　kJ/mol.　In　addition,　the　conduction　mechanism　of　the　CSP-SPS　and　SPS　samples　is　investigated　using　impedance　spectroscopy.　Overall,　CSP-SPS　is　promising　for　the　fabrication　of　fine　ceramics　with　mild　sintering　conditions.　©　2022　Elsevier　Ltd