Due to the growing need for more natural medicines as a result of population growth and lifestyle improvement as well as reducing unwanted side effects of fully synthetic medicines. Plants are very important sources of many valuable bioactive compounds that benefit human and animal health. So, this study aimed to investigate Foeniculum vulgare seeds extract to estimate its antimicrobial, antitumor, antioxidant, and antiviral activities. The extraction process was performed by grinding the plant powder in ethanol (60%). A wide range of bioactivities was evaluated as antimicrobial activity against indicator bacterial, and fungal strains followed by antioxidant activity evaluation by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method and finally, MTT assay to determine antitumor activity using 5 different cell lines; the breast tumor cell line (MCF-7), cervical cancer cell line (HELA), colon cancer cell line (CACO-2), lung cancer cell line (A549), and hepatocellular carcinoma cell line (HEPG-2) in corresponding to the normal cell line (Wi-38).. As well, antiviral activity was evaluated against HSV and CoxB4. Fortunately, ethyl extract exhibited promising antimicrobial activity against the selected pathogenic microorganisms, antioxidant activity exhibit IC50 at 28.71 µg/ml. Regarding its antitumor activity, it exhibited promising anticancer activities against all tested carcinoma cell lines and their IC50 ranged from 248.0 to 815.1 µg/ml in corresponding to 828.1 µg/ml for the normal cells reflecting a potential anticancer potential. Regarding antiviral activities of fennel extract, it showed moderate antiviral activities 21.95% and 13.14% against the HSV and CoxB4 viruses respectively. Conclusively, fennel exhibited promising results as antitumor agents with significant activity as antimicrobial, antioxidant, and antiviral which encourages us to recommend the administration of fennel as a drink or food to protect the body and provide it with valuable compounds.