Oral and oropharyngeal cancers remain significant global health concerns, with well-established risk factors including tobacco and alcohol use, along with others such as areca nut chewing, HPV infection, and poor oral hygiene. The association between cannabis consumption and oral carcinogenesis is still under investigation. However, cannabinoids are increasingly used by cancer patients for symptom relief, and recent studies suggest they may modulate cancer-related pathways through alterations in microRNA (miRNA) expression. miRNAs, in turn, can influence the endocannabinoid system. Saliva, a readily accessible and noninvasive biofluid, offers a promising medium for detecting changes in miRNA profiles linked to oral cancer and premalignant conditions. These salivary miRNAs may serve as early diagnostic biomarkers and help predict disease outcomes. This chapter explores the current evidence on the relationship between cannabis use, salivary miRNA expression, and the development of oral cancer, underscoring the potential of salivary miRNAs in early detection and prognosis.