Hybrid structures containing multiple pharmacophore units with known activity have attracted attention due to their promising outcomes. In this study, several new hybrid structures containing benzimidazole and thiadiazole units were synthesized. The newly synthesized compounds were structurally analyzed using1 H-NMR,13 C-NMR, HRMS, and elemental analysis. The antimicrobial, in vitro anti-cancer, and antioxidant activities of all compounds were investigated. In vitro antimicrobial activities of the compounds were determined against Gram-positive (S. aureus ATCC 29213, E. faecalis ATCC 29212), Gram-negative (E. coli ATCC 25922, P. aeruginosa ATCC 27853) bacteria and fungi (C. albicans ATCC 10231) by using broth microdilution method. The compound 5g bearing 4-methoxyphenyl derivative showed the best activity with 32 μg/mL against S. aureus ATCC 29213 and P. aeruginosa ATCC 27853. The MTT test was used to determine the cytotoxicity of the produced compounds on the MCF-7 (human breast cancer) and L-929 (fibroblast) cell lines. FRAP method was used to determine the antioxidant properties of synthesized compounds. The Ferric Reducing Antioxidant Power of the compounds 5a, 5b, and 5c showed more antioxidant properties than vitamin E. The compound 5g stands out in the series in that it is not toxic on the healthy cell line and has promising antimicrobial activity.