The improvement of a green synthetic approach that focuses on the use of olive leaf extract took place to produce silver nanoparticles (AgNPs). This synthesis is known for its cost efficiency and ecological safety, with the potential to be applied in massive AgNP production. The cytotoxic, anticancer, and antioxidant activities of olive leaf extracts with AgNPs were examined on breast cancer cell lines following preparation of olive leaf extracts utilizing a method of extraction at a temperature of (0°C/8 h). Total flavonoids and phenolics for olive leaves with extraction through ethanolic and water solvents were 43.52  mg  /  ml and 132.9 and 64.73  mg  /  ml and 293.32, respectively. UV-Vis spectroscopy that has the sizes of absorption peaks from 420 to 440 mm was used to describe the synthesized AgNPs nanoparticles. Scanning electron microscopy verified these particles, specifying that they are characterized by the spherical shape of and being 100 nm on average. AgNPs’s antioxidant activity was significant. Additionally, a cytotoxic activity dependent on concentration was shown by green synthesized AgNPs. This is the initial study that established olive leaf extracts biological activity at 0°C/8 h temperature utilizing ethanol and water solvents followed by biosynthesized AgNPs from the extracts and their therapeutic potential.