This paper proposes a new three-dimensional optimal guidance law for impact time con-trol with seeker’s Field-of-View (FOV) constraint to intercept a stationary target. The proposed guidance law is devised in conjunction with the concept of biased Proportional Navigation Guid-ance (PNG). The guidance law developed leverages a nonlinear function to ensure the boundedness of velocity lead angle to cater to the seeker’s FOV limit. It is proven that the impact time error is nullified in a finite-time under the proposed method. Additionally, the optimality of the biased com-mand is theoretically analyzed. Numerical simulations confirm the superiority of the proposed method and validate the analytic findings.