Low sintering-temperature lead-free particulate composites of (1 − x)(0.98(Bi0.5(Na0.78 K0.22)0.5TiO3 − 0.02CuO) − (x)CoFe2O4(x = 0–0.15) were synthesized by a combination of sol–gel and solid-state sintering methods. Structural, morphological, ferroelectric, and ferromagnetic properties of the composites were systematically investigated using different techniques. XRD results and FE-SEM images indicated the formation of single phase for parent matrix and the development of two component phases in all composites without any impurities. With increasing CoFe2O4 (CFO) content, P–E loops displayed a gradual increase in the coercive field (Ec). The ferroelectric properties of BNKTC were significantly reduced with increasing CFO content, evidenced by a slight decrease in saturated polarization (Ps), and a sharp reduction in normalized strain (Smax/Emax) and piezoelectric constant (d33). Conversely, M-H loops showed a remarkable improvement in ferromagnetism with increasing CFO content, which is a good sign for searching multiferroic composites.