Ticks are obligatory blood-sucking ectoparasites of a wide variety of animals, and they cause economic losses in livestock breeding by acting as vectors of some bacterial, protozoan and viral pathogens. In the current study, tick-infested sheep was investigated. For this purpose, 4115 sheep from all provinces of Turkey were examined for tick infestation. A total of 1575 adult ticks were collected from 24 different provinces between April and October 2017. Tick infestation rate was determined as 8.8% (n: 362). No argasid ticks were encountered among the collected ticks. Six tick species were morphologically identified belong to Ixodidae, namely as Rhipicephalus turanicus (90.86%), Rhipicephalus bursa (4.32%), Rhipicephalus sanguineus (0.19%), Hyalomma excavatum (4.32%), Hyalomma marginatum (0.25%) and Dermacentor marginatus (0.06%). This study reveals that Rh. turanicus is more abundant than the other species causing infestations in sheep, and reports the tick infestation in sheep for the first time in some provinces (Antalya, Ardahan, Aydın, Batman, Bursa, Denizli, Isparta, İzmir, Kahramanmaraş, Kırşehir, Manisa, Muğla, Nevşehir, Uşak, Yalova ve Yozgat) of the country.