In this work, a flexible, low cost, and cleanroom-free technique to fabricate barium titanate (BaTiO3) hybrid p–n homojunction-based multifunctional sensor for photodetection, strain sensing, and chemiresistive sensing is reported. The n-type BaTiO3 nanofibers are synthesized using electrospinning technique and deposited on the flexible indium tin oxide (ITO) using spin-coating method while p-type BaTiO3 nanoparticles are synthesized using modified sol–gel method and deposited using drop-casting method. Detailed characterization studies are performed to reveal the formation of tetragonal phase p-type nanoparticles and n-type nanofibers of BaTiO3 assembled on the ITO substrate. The fabricated hybrid junction photodetector displays an excellent external quantum efficiency of ≈3500 and photoresponsivity of ≈11 A W−1. Further, the hybrid junction when employed as strain sensor exhibits a gauge factor of 14 and when operated in chemiresistive sensing mode can detect α1-acid glycoprotein with an excellent sensitivity of 49.7 µm−1 in the wide dynamic range of 0.05–10 × 10–6 m and detection limit of 12 × 10–9 m. Detailed studies to understand the underlying mechanism of operation for each application are done. The strategy outlined here can be further employed for sensing various physical and chemical stimuli, paving a new path for developing flexible multifunctional nanoelectronic devices. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim