The incorporation of two-dimensional (2D) perovskites into three-dimensional (3D) perovskite has been demonstrated to markedly enhance the power conversion efficiency and long-term stability of perovskite solar cells (PSCs). However, the inferior out-of-plane charge transport resulting from the insulation of organic spacer layers represents the major impediment to the photovoltaic performance of 2D/3D perovskite solar cells. Herein, we introduce 2D ferroelectric perovskite (DFP)₂PbI₄ as seeds, enabling the regulation of the crystallization process of the 3D perovskite and resulting in high-quality perovskite films with larger domains of preferential crystalline orientation. Meanwhile, owing to the ferroelectric effect of (DFP)₂PbI₄, the built-in potential in 2D/3D perovskite is increased, resulting in an improvement in device performance. PSCs fabricated with the 2D ferroelectric perovskite show enhanced performance with power conversion efficiency of 25.31 %. The devices also exhibit improved stability, maintaining over 80 % of their initial efficiency for 1000 h under maximum power point tracking. This work establishes a promising approach to utilizing 2D ferroelectric perovskite for regulating the crystallization of perovskite and combining molecular ferroelectrics with PSCs.