Cyanistes caeruleus, commonly known as the Eurasian Blue Tit, is native to a wide range of regions across Europe and parts of the western Palearctic region, including North Africa and parts of the Middle East. It is found throughout most of Europe, excluding the northernmost reaches, and extends eastward into western Russia and parts of the Caucasus region.

The Eurasian Blue Tit typically inhabits temperate environments, often found in deciduous or mixed forests, especially where oak trees are present. It also thrives in parks, gardens, and urban areas where suitable tree cover is available. The species is accustomed to a climate that varies from mild to moderately cold, with cool winters and warm summers.

Eurasian Blue Tits play a critical role in the ecosystem as insectivores, feeding predominantly on caterpillars, moths, and other small invertebrates during the breeding season, which helps control pest populations. Outside of the breeding season, their diet becomes more varied and includes seeds and nuts. These birds are also known for their acrobatic feeding habits, often seen hanging upside-down to access food.