In the past few decades, transparent electro-optical ceramics PLZT (9/65/35) (Pb0.91La0.09(Zr0.65Ti0.35)0.9775O3) with special properties, particularly high transmittance in visible light, have gained much attention. However, restricted by the large ferroelectric hysteresis, the prospect is not optimistic. In this article, Pb0.91La0.09(Zr0.65Ti0.35)0.9775-5x/4NbxO3 (abbreviated as PLZTN) transparent ceramics with varying Nb content (x = 0.000, 0.005, 0.010, 0.015) were fabricated by hot press sintering process under oxygen atmosphere. Electrical and optical properties were systematically studied. The temperature dependence of the dielectric constant showed a diffuse phase transition indicated typical relaxor behaviour. Moreover, the temperature at maximum dielectric constant (Tm) are near about 63 °C, almost unchanged. Comparing with undoped samples, the PLZTN with x = 0.010 Nb doping shows a dramatic reduction of 162.5% in ferroelectric hysteresis, with only a slight decrease in the maximum polarization from 30.04 µC/cm2 to 28.53 µC/cm2. The quadratic electro optic coefficient experienced 54.8% reduction but still satisfy the application requirements. In terms of transmittance, the PLZTN samples kept a high value of transmittance (about 64%) along with increasing Nb content. Hence, the conclusion can be drawn that Nb doping in PLZT (9/65/35) is a novel strategy to reduce the ferroelectric hysteresis.