Illinois (/ ˌɪləˈnɔɪ / (Game da wannan waƙar sautin) IL-ə-NOY) jiha ce a yankin Midwest na Amurka. Tana da ƙasa mafi girma ta biyar (GDP), na shida mafi yawan jama'a, da kuma yanki na 25 mafi girma na duk jihohin Amurka. An lura da Illinois a matsayin matsakaiciyar kwayar halittar Amurka baki daya. Tare da Chicago a arewa maso gabashin Illinois, ƙananan biranen masana'antu da ƙarancin albarkatun noma a arewa da tsakiyar jihar, da albarkatun ƙasa kamar kwal, katako, da man fetur a kudanci, Illinois tana da tushen tattalin arziki daban-daban, kuma babbar matattarar sufuri ce. Tashar jiragen ruwa ta Chicago ta haɗu da jihar zuwa tashar jiragen ruwa ta duniya ta manyan hanyoyi biyu: daga Manyan Tafkuna, ta hanyar Saint Lawrence Seaway, zuwa Tekun Atlantika kuma daga Manyan Lakes zuwa Kogin Mississippi, ta Kogin Illinois, ta hanyar Kogin Illinois. Kogin Mississippi, da Kogin Ohio, da Kogin Wabash sune sassan iyakokin Illinois. Shekaru da dama, Filin jirgin saman O'Hare na Chicago yana cikin ɗaya daga cikin filayen tashin jirage mafi birgewa a duniya.