Herein, a nanofiber network of La1−xCexCoO3 (x = 0, 0.05, 0.1 and 0.2) was prepared using the electrospinning-calcination method. X-ray diffraction patterns revealed the appearance of CeO2 with increasing Ce-substitution. The gas sensing measurements established that the combination of the nanofiber morphology and catalytic effect of Ce imparts greater ethanol sensing performance, particularly for the highest Ce-substitution level of La0.8Ce0.2CoO3 with enhanced response of 83.4, coupled with great selectivity, along with swift response and recovery time of 17 and 32 s at a low operating temperature of 100 °C. The particle-interconnected nanofiber morphology as observed from scanning electron microscopy presented exceptional large hole depletion layers (HAL) which allowed for HAL overlapping with each other thus promoting greater resistance changes. Furthermore, the Ce-substitution caused a deviation from the stoichiometry and increased the surface oxygen defects that created more active surface area which promoted a more advanced gas and surface interaction. This work demonstrates the potential ethanol sensing capabilities of La1−xCexCoO3 induced by Ce-partial substitution on the La-site.