To elucidate the impact of a high entropy elemental distribution of the lattice site on the magnetic properties in oxide compounds, a series of complex perovskites BaBO3 (B = Y, Fe, Ti, Zr, Hf, Nb, and Ta) with different Fe content ratios (0, 0.2, 0.3, and 0.4) have been synthesized and thoroughly characterized. In this complex oxide series, superconducting quantum interference device magnetometry reveals a gradual change of a well-defined magnetic phase transition and B-site magnetic moment, which correlates with the Fe content. More importantly, a comprehensive analysis of the sample with a 0.4-Fe content (40% on the B-site) including magnetization, heat capacity, neutron diffraction, and muon-spin rotation measurements suggests that in the low-temperature state, a short-range antiferromagnetic correlation may exist, which could result from the magnetic interaction of Fe ions and consequent redistribution of associated d-electrons.