Chemiresistive sensors fabricated by oleylamine-functionalized palladium nanoparticles (OLA-PdNP) have been studied in hydrogen sensing, but not so much in organic vapor sensing. Like the extensively studied gold nanoparticles-based gas sensors, palladium nanoparticles also give the ease of surface modification and large surface-area-to-volume ratio. In this study, we demonstrate an OLA-PdNP chemiresistor array with robust sensor responses (1-15% of ΔR/R₀) and accurate discrimination of six organic vapors at a concentration of p/p₀ = 0.2, using principal component analysis (PCA). Each microfabricated 36 mm² chip has 36 individual sensors. By incorporating multiple sensors on one chip, the sensor response gives a distinguishable pattern for each analyte. From this study, an electronic chemical spectrometer can be further developed by incorporating many types of ligands on palladium metal core to enhance sensor accuracy and precision.