Background and Objective: Lemongrass (Cymbopogon citratus) and turmeric (Curcuma longa) are widely used by the community for traditional medicinal spices and cooking spices. In the era of the COVID-19 pandemic, people use lemongrass and turmeric to increase immunity and protect the body from infection with the SARS-CoV-2 virus. However, the antiviral mechanisms have not been studied much. This study aims to predict the bioactivity of the phytosterol compounds of lemongrass and turmeric for COVID-19 therapy through inhibition of 3C-like protease (3CLPro) in silico. Materials and Methods: The 3CLPro protein 3D structure was downloaded from the PDB database with the access code 2ZU2 and the phytosterol compounds of lemongrass and turmeric were taken from PubChem. A total of 59 total phytosterol compounds from turmeric and lemongrass were screened for their bioactivity as an antiviral by using online PASS.Compounds with a high activating potential (Pa) were interacted with 3CLPro protein with the PyRx program and analyzed by Discovery Studio version 19.0 and LigPlus. Results: A total of 22 total phytosterol compounds were identified as potential antiviral agents. Based on the Pa value, 15 phytosterol compounds have the potential to act as inhibitor agents for 3CLPro SARS-CoV-2. The phytosterol compounds of lemongrass and turmeric bind to the 3CLPro protein in the N-finger domain region and the A and B domain inhibitors connect residues of the 3CLPro protein. The phytosterols of lemongrass and turmeric show a low binding affinity with 3CLPro SARS-CoV-2, indicating a strong interaction between ligand and protein. The inhibition of phytosterols against 3CLPro protein can be used as a basis for determining candidates for COVID-19 therapeutic agents. Conclusion: The phytosterol compounds contained in lemongrass and turmeric have the potential to act as 3CLPro inhibitors. Further studies both in vitro and in vivo need to be done to prove the inhibitory potential of phytosterol compounds.