Despite the importance of olive trees in Tunisia, very little is known about mite populations. A survey of phytophagous and predatory mites species in 21 orchards distributed over several sites was conducted from 2007 to 2013. During this study, 14 species of predatory mites along with 5 species of phytophagous mites were collected and identified. Almost all species are newly identified from olive trees, five of them are new to the Tunisian fauna and one species is new to Science. This paper provides a catalogue of these species and elements on their biogeographical distribution and biology. Identification keys are also provided. The Phytoseiidae species described in this study may provide new opportunities for the integrated pest management of Eriophyidae and Tenuipalpidae mites on olive trees.