Four high entropy alloys (FeMnCrNi system HEAs) with different Al and Ti contents were fabricated via vacuum induction melting using low-cost ferroalloys and pure metals. The influence of Al and Ti on inclusion characteristics was analyzed using an electrolytic extraction process in combination with scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) characterization. The obtained results showed that in Ti-free (Fe50Mn30Cr10Ni10(S1) and Fe44Mn30Cr10Ni10Al6 (S2)) HEAs, the main inclusions were MnS, Al2O3, and Al2O3-MnS, which were irrelevant of Al content. In Ti-containing HEAs, aggregated Ti(CxN1−x) inclusions were formed, along with Al2O3-Ti(CxN1−x) and Al2O3-TixOy-Ti(CxN1−x) complex inclusions regardless of Ti content. Non-equilibrium thermodynamic calculations revealed that Ti, C, and N segregated at the solidification front, driving the precipitation of Ti(CxN1−x), and the composition of Ti(CxN1−x) in Fe44Mn30Cr10Ni10Ti6(S3) and Fe44Mn30Cr10Ni10Ti2Al4(S4) was very similar to that of TiC. Inclusion growth modeling indicated that faster cooling rates produced smaller inclusions, while higher Ti content led to larger sizes. Due to aggregation effects, the experimentally observed inclusion sizes exceeded those predicted by theoretical models. Collision and aggregation modeling further revealed that the S3 alloy exhibited a higher number density of Ti(CxN1−x) inclusions, which increased the collision frequency among inclusions and consequently promoted the aggregation process. Reducing Ti content could suppress Ti(CxN1–x) inclusion growth during solidification, and also could decrease their number density, collision frequency, and aggregation. The obtained results of this study provide a theoretical basis for controlling the inclusions in Al-Ti containing high entropy alloys manufactured by low-cost feedstocks