A novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method with a dual electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) source was developed for analysis of 66 pesticides and 5 mycotoxins regulated by the State of California in medium-chain triglyceride (MCT) oil cannabis tinctures. The limits of quantitation (LOQs) of all of the pesticides and mycotoxins were well below California state action limits of these analytes in cannabis-based non-inhalable or edible products. A total of 62 (out of 66) pesticides and 5 mycotoxins were analyzed using LC–MS/MS with an ESI source, and the remaining 4 pesticides were determined using LC–MS/MS with an APCI source. A simple, fast, and cheap acetonitrile solvent extraction method was used for sample preparation to get good recovery and achieve high throughput for this analysis. For late-eluted analytes, a number of internal standards were used to compensate for ion suppression effects from the hydrophobic matrix.