The voltage gated sodium channel comprises a pore‐forming α subunit and regulatory β subunits. We report here the identification and characterization of a novel splicing variant of the human β₁ subunit, termed β_1B. The 807 bp open reading frame of the human β_1Β subunit encodes a 268 residue protein with a calculated molecular mass of 30.4 kDa. The novel human β_1B subunit shares an identical N‐terminal half (residues 1–149) with the human β₁ subunit, but contains a novel C‐terminal half (residues 150–268) of less than 17% sequence identity with the human β₁ subunit. The C‐terminal region of the human β_1B is also significantly different from that of the rat β_1A subunit, sharing less than 33% sequence identity. Tissue distribution studies reveal that the human β_1Β subunit is expressed predominantly in human brain, spinal cord, dorsal root ganglion and skeletal muscle. Functional studies in oocytes demonstrate that the human β_1B subunit increases the ionic current when coexpressed with the tetrodotoxin sensitive channel, Na_V1.2, without significantly changing voltage dependent kinetics and steady‐state properties, thus distinguishing it from the human β₁ and rat β_1A subunits.