The best‐recorded performance of perovskite‐based solar cells (PSCs) in regular mesoscopic architecture is generally associated with the use of the common 2,2′,7,7′‐tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9′‐spirobifluorene (Spiro‐OMeTAD). However, the need for lithium‐based hygroscopic dopants hinders the chemical and environmental stability of the devices. This work presents a passivated stable PSC device based on a dopant‐free poly(3‐hexylthiophene) (P3HT) hole transport layer. By introducing a poly(N,N′‐bis‐4‐butylphenyl‐N,N′‐biphenyl)benzidine (polyTPD) interlayer at the perovskite/P3HT interface, the parameters of the low‐performance pristine P3HT‐based cells are improved. This introduction leads to optimizing the P3HT film morphology, interfacial defects, and charge extraction, along with a significant suppression of interfacial recombination and enhancement of the cell power conversion efficiency (PCE) from 7% to 10.65%. Further, an improvement is observed in open‐circuit voltage and the fill factor, increasing from 0.912 to 0.95 V and from 59.2% to 61.1%, respectively. Moreover, the noncapsulated passivated PSC devices exhibit higher operational stability. Examinations show that devices in a dark controlled environment (10–15% humidity) can retain 82% of their initial PCE for 450 h, and 73% of their initial PCE when thermally stressed at 60 °C temperature under ambient conditions (25–35% humidity) for 264 h.