The goal of this study was to determine the composition of olive oils from four North Moroccan provinces (Larache, Chefchaouen, Ouazzane and Tetouan), one of the main productive zones nationwide. For this purpose, we evaluate the quality parameters, phenolic compounds, oxidative stability, fatty acids, sterols, uvaol + erytrodiol, carotenoids and chlorophylls of three varieties (‘Picholine marocaine’, ‘Haouzia’ and ‘Menara’) in three campaigns (2019/2020 to 2021/2022) and in three harvesting periods. Another aim was to research the effect of natural microtalc (NMT) on the compounds of olive oils, and to evaluate whether the addition of microtalc to olive pastes during the malaxation stage influences in the quality of olive oils. From the results, it was observed that industrial yields increase when natural microtalcs were used during the oil production. Considering the quality parameters, the olive oils produced with NMT showed lower values when compared with those obtained without any addition. Also, oils produced with NMT showed a higher content in phenolic compounds as well as a greater oxidative stability. It is worth highlighting that the maximum content in phenolic compounds, adding NMT during the extraction process, was determined in oils obtained from the ‘Picholine marocaine’ variety from Chefchaouen, harvested in the 2019/2020 campaign, with 848.71 mg/kg oil, with a value of oxidative stability of 78.68 h.