Tungsten bronze (TB) structural ceramics with the nominal formula Ba4-xSm2Fe2-xNb8+xO30 (BSFN) (x = 0, 0.025, 0.05, 0.075 and 0.1) were prepared using a standard solid-state sintering method. The effects of Ba2+ concentration on the crystallographic phase, microstructure, dielectric and ferroelectric properties were systematically studied. All compounds presented tetragonal tungsten bronze (TTB) structures, where the A1 and A2 sites were exclusively occupied by Sm3+ and Ba2+ ions, respectively, while the Fe3+ and Nb5+ ions were randomly distributed between the B1 and B2 sites. All BSFN ceramics exhibited normal ferroelectric behavior, but the dielectric properties showed an increasing dispersion as the concentration of Ba2+ decreased. The conductive behavior was due to the bulk and grain boundaries, and the direct current conductivity was increased from 0.67 to 0.77 eV with a reduction in the concentration of Ba2+. The polarization-electric field (P-E) and current-electric field (I-E) loops of all the BSFN ceramics showed ferroelectric behavior, and the P-E loops became more slanted and slimmer with reduced Ba2+ concentration.