This study aimed to investigate the effect of Moroccan saffron (Crocus sativus) floral by-products on the causal agent of bacterial canker of tomato caused by Clavibacter Michiganesis Subsp. Michiganensis (CMM). This work intends to replace chemical treatment methods with ecological, safe, and less expensive methods using extracts of saffron by-products. The phytochemical screening and the antioxidant activity of saffron by-products were studied. Moreover, the antibacterial activity of ethanolic extracts of saffron by-products was determined using the agar well diffusion method. The results showed that the ethanolic extracts of saffron by-products constitute a significant source of bioactive molecules endowed with antioxidant activity. Further, all the tested saffron extracts inhibited the bacterial growth of (CMM) with an inhibition zone diameter ranging from 3 to 31 mm. Thus, this study aimed to valorize the saffron by-products generated after the harvest of the stigmas, in the biological treatment of tomato diseases.