Several phytoseiid species are excellent biological control agents for suppressing mite pest populations in many crops and preventing yield losses. This paper aims to improve the knowledge of Phytoseiidae diversity in citrus orchards and argan forest in central western Morocco. The surveys were conducted between April and October during three successive years (2017–2019), in nine conventional citrus orchards covering an area of more than 3,000 hectares and on uncultivated plants in argan forest at an altitude ranging from 150 to 700 meters. Twenty-nine species belonging to 15 genera were found, seven of them being new for the Moroccan fauna: Amblyseius largoensis, A. swirskii, Amblyseiella setosa, Euseius batus, E. dossei, Paragigagnathus molestus, and Cydnoseius negevi. Species of nine genera were found on citrus leaves: Neoseiulus, Amblyseius, Amblyseiella, Transeius, Phytoseiulus, Euseius, Phytoseius, Typhlodromus, and Paraseiulus. Stah AlMadina (24.8%), Ouled Abdellah (15.9%), Nour (14.3%) domains contained a high number (more than 60.2%) of individuals in the collected samples. Malva parviflora, Convolvulus althaeoides, Solanum nigrum, Bryonia dioica, Withania somnifera would be interesting companion plants to be associated in the inter-rows in citrus orchards in this region to ensure sustainability, because they host high densities and diversities of Phytoseiidae. A key of females of all recorded Moroccan species until now is provided.