Barium stannate titanate [Ba(SnxTi1-x)O3, x=0.1, 0.2, 0.3, and 0.4] ceramics were prepared using a conventional solid-state reaction process. Their dielectric properties were measured under direct current bias fields ranging from 0 to 2.5 kV/cm. A transformation from normal to relaxor ferroelectrics was observed when x≥0.3. Broken long-range order or "dirty" ferroelectric domains and nanodomains were observed in Ba(Sn0.1Ti0.9)O3 and Ba(Sn 0.4Ti0.6)O3 by transmission electron microscopy, respectively. Voltage driven tunability was found to decrease with increasing Sn content. The change from normal ferroelectric into relaxor ferroelectric had a negative impact on the tunability value of the materials.