Hard ticks are among the most important blood sucking arthropods that transmit pathogens to humans and animals. This study was designed to determine prevalence, mapping, geographical distribution, and seasonal activity of hard tick species infesting the most common domestic and wild mammals in various districts of Riyadh Province, Saudi Arabia, during the period January to December 2017. In total, 10,832 adult hard ticks were collected from the bodies of 8,435 animals belonging to 18 different mammalian species. The ticks were preserved in 70% alcohol and microscopy was used to identify species. Two genera, Hyalomma and Rhipicephalus, were identified, comprising 10 species of hard ticks, with Hyalomma comprising 68.3% and Rhipicephalus comprising 31.7% of species. The most common species on domestic mammalian hosts was Hyalomma dromedarii (Koch 1844) (39.9%) followed by Rhipicephalus turanicus (Pomerantsev, Matikashvili & Lotosky 1936) (34.9%), whereas on wild mammalian hosts Rhipicephalus sanguineus (Latreille 1806) was by far the most prevalent species (83.0%). However, ticks were most abundant during May through July (36.0%) in the studied areas, and tick intensity and abundance differed among seasons. Our results provide information for human and animal health service managers, as well as governmental authorities, to gain a better understanding of hard ticks infesting mammalian hosts in Riyadh Province, Saudi Arabia, which can help improve prevention and control of tick-borne diseases, especially during outbreaks.