Electrical conductivity (EC) and percolation threshold of chopped carbon fiber (CF)-carbon nanotube (CNT)-reinforced epoxy multiscale nanocomposites considering tunneling resistivity are studied based on micromechanics. The percolation theory is applied to determine transition from low to high conductivity. Influences of CNT/polymer interphase and CNT waviness are considered to evaluate percolation threshold of CNT-enriched epoxy nanocomposite prior to CF percolation threshold. Multiscale fillers provide benefit of enhanced EC with different percolation thresholds for different fillers. These characteristics of multiscale filler with high aspect ratio of filler facilitate formation of conductive network even at low multiscale filler volume fraction. Variation of EC as a function of tunneling distance, CNT and CF aspect ratios and intrinsic EC for different CNT volume fractions is investigated. The nanocomposite exhibits a percolation threshold at less than 0.2 vol% of CNTs. The percolation threshold is predicted to be reduced when higher volume fractions of CFs are considered.