The first-line chemotherapy is associated with chief shortfalls such as non-specific distribution causing severe dose-dependent toxicities and development of tumor resistance. The current preliminary study aimed to identify the safe and effective non-oncology drugs as an alternative to toxic chemotherapeutics to treat osteosarcoma, and overcome new drug's shortage and development challenges. The different category non-oncology drugs (alone and in combinations) were screened for in vitro cytotoxicity behavior via MTT dye reduction assay and cell cycle arresting behavior using flow cytometer against human osteosarcoma (Saos-2 and MG-63) cells. The molecular docking of selected therapeutics was executed against cyclin-dependent kinase 1 (CDK1), cell cycle regulator overexpressed in cancer. The identified combination was further tested for in vivo toxicities in rats at two different doses. The current study revealed niclosamide (NSD), ketoconazole (KCZ), simvastatin (SVN) combination that causes substantial cytotoxicity (IC50 values are in picomoles) at 1:1:3 molar ratio when compared to other molar ratios. This combination has also caused substantial arrest of Saos-2 and MG-63 cells at S and G2/M phase. Additionally, all three drugs demonstrated better interaction with CDK1 indicating anticancer potential via inhibition of CDK1. Furthermore, the in vivo toxicity study revealed no significant changes in hematological and biochemical parameters, body weights of rats, weights of vital organs, daily food and water intake, and general behavior of rats. The obtained preliminary results revealed the potential application of this combination on non-oncology drugs in the safe and effective treatment of osteosarcoma. However, further in-depth studies are required before clinical application.