Poecile montanus, commonly known as the Willow Tit, is native to the Palearctic region. Its geographical distribution includes parts of Europe and Asia, stretching from western Europe through Scandinavia and Siberia to the eastern parts of Russia. The species can also be found in the northern regions of Japan and Korea.

The Willow Tit typically inhabits coniferous and mixed forest environments, often preferring areas with dense undergrowth. These areas usually include subarctic and temperate climates characterized by cold winters and mild summers. The species is often found in lowland regions but can also adapt to higher altitudes given the right forest conditions.

This bird is primarily a cavity nester and is known for excavating its own nest holes in decaying wood, which positions it uniquely in the forest ecosystems. The Willow Tit feeds on insects and seeds, playing a crucial role in pest control and the dispersal of plant seeds. Seasonal variations in diet reflect its adaptability to different environmental resources throughout the year.