Tree worship (dendrolatry) refers to the tendency of many societies throughout history to worship or otherwise mythologize trees. Trees have played an important role in many of the world's mythologies and religions, and have been given deep and sacred meanings throughout the ages. Human beings, observing the growth and death of trees, the elasticity of their branches, the sensitivity and the annual decay and revival of their foliage, see them as powerful symbols of growth, decay and resurrection. The most ancient cross-cultural symbolic representation of the universe's construction is the world tree.

The image of the Tree of life is also a favourite in many mythologies. Various forms of trees of life also appear in folklore, culture and fiction, often relating to immortality or fertility. These often hold cultural and religious significance to the peoples for whom they appear. For them, it may also strongly be connected with the motif of the world tree.

Other examples of trees featured in mythology are the Banyan and the Peepal (Ficus religiosa) trees in Hinduism, and the modern tradition of the Christmas Tree in Germanic mythology, the Tree of Knowledge of Judaism and Christianity, and the Bodhi tree in Buddhism. In folk religion and folklore, trees are often said to be the homes of tree spirits. Historical Druidism as well as Germanic paganism appear to have involved cultic practice in sacred groves, especially the oak. The term druid itself possibly derives from the Celtic word for oak.