The effects of the yttrium nitrate (YN) content on nitrogen doping and the electrical resistivity of SiC ceramics were investigated. The YN was found to be an effective sintering additive for the full densification of SiC ceramics by hot‐pressing. The hot‐pressed bulk samples were identified as polycrystalline zincblende β‐SiC with a small amount of α‐SiC and Y2O3 crystallites. The SiC grains contained nitrogen (N) as an impurity that contributed to the decrease in electrical resistivity of the samples. An optimum YN composition exists for which the N concentration is maximized to give the lowest resistivity. The SiC samples exhibited a resistivity as low as ~10−3 Ω·cm and a carrier density of ~1020 cm−3, which was excited from the N donor levels. The resistivity of the samples was maintained in the same order of magnitude over a wide temperature range (4–300 K).