Composites with promising electrical and magnetic properties have dragged the attention of the current research interest as compared to the single-phase material due to their potential applications in sensor and charge storage devices. Hence, composites (1− x )Bi 5 Ti 3 FeO 15 −( x )La 0.67 Sr 0.33 MnO 3 with different compositions ( x  = 0, 0.1, 0.2, 0.3, and 0.4) are investigated via the sol–gel precursor hybrid method. The structural analysis and phase purity of the composites are examined by the Rietveld refinement of X-ray diffraction spectra. This reveals the existence of the Bragg peaks corresponding to the perovskite (BTFO) as well as the manganite (LSMO) phase. The strain at the interface of the BTFO and LSMO phases causes the change in lattice parameters and shifting of phonon modes in the Raman spectra. X-ray photoelectron spectroscopy (XPS) confirms the mixed-valence state of Mn 3+ /Mn 4+ and Fe 3+ /Fe 2+ ions, endorsing the oxygen vacancies in the prepared composites. The dielectric permittivity increases with the increase of the LSMO phase, which is ascribed to interfacial lattice strain. Using the modified Debye model, the dispersive behavior of frequency-dependent dielectric permittivity is explained. Room temperature M–H data reveal the enhancement of M r (~4.74 × 10 –3  emu/g) by 13 times and M max (~ 0.415 emu/g) by 6 times for 40% LSMO composite which is ascribed to the inclusion of the manganite (LSMO) phase. Theoretically, the magnetization value is also estimated from Vegard’s law and compared with the experimental result.