Background: Cannabis sativa is a psychoactive plant indigenous to Central and South Asia, traditionally used both for recreational and religious purposes, in addition to folk medicine. Cannabis is a rich source of natural compounds, the most important of which are commonly known as cannabinoids that cause a variety of effects through interaction with the endocannabinoid system. Materials and Methods: In this study, a high-performance liquid chromatography-ultraviolet/photodiode array (PDA) method was developed and validated for the analysis of 15 cannabinoids in cannabis plant materials and cannabis-based marketed products. These cannabinoids are cannabidivarinic acid, cannabidivarin, cannabidiolic acid, cannabigerolic acid, cannabigerol, cannabidiol, delta-9-tetrahydrocannabivarin, delta-9-tetrahydrocannabivarinic acid, cannabinol, delta-9-tetrahyrocannabinol, delta-8-tetrahyrocannabinol, cannabicyclol, cannabichromene, delta-9-tetrahyrocannabinolic acid A, and cannabichromenic acid. The separation was carried out using a reversed-phase Luna® C18(2) column and a mobile phase consisting of 75% acetonitrile and 0.1% formic acid in water. A PDA detector was used, and data were extracted at λ=220 nm. Principal component analysis of cannabis four varieties was performed. Results: The method was linear over the calibration range of 5-75 μg/mL with R2>0.999 for all cannabinoids. This method was sensitive and gave good baseline separation of all examined cannabinoids with limits of detection ranging between 0.2 and 1.6 μg/mL and limits of quantification ranging between 0.6 and 4.8 μg/mL. The average recoveries for all cannabinoids were between 81% and 104%. The measured repeatability and intermediate precisions (% relative standard deviation) in all varieties ranged from 0.35% to 9.84% and 1.11% to 5.26%, respectively. Conclusions: The proposed method is sensitive, selective, reproducible, and accurate. It can be applied for the simultaneous determination of these cannabinoids in the C. sativa biomass and cannabis-derived marketed products.